<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<!-- Generated by HsColour, http://www.cs.york.ac.uk/fp/darcs/hscolour/ -->
<title>Blaze/ByteString/Builder/Internal.hs</title>
<link type='text/css' rel='stylesheet' href='hscolour.css' />
</head>
<body>
<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE CPP, BangPatterns, Rank2Types, MonoPatBinds #-}</span>
<a name="line-2"></a><span class='hs-comment'>-- |</span>
<a name="line-3"></a><span class='hs-comment'>-- Module : Blaze.ByteString.Builder.Internal</span>
<a name="line-4"></a><span class='hs-comment'>-- Copyright : (c) 2010 Simon Meier</span>
<a name="line-5"></a><span class='hs-comment'>-- License : BSD3-style (see LICENSE)</span>
<a name="line-6"></a><span class='hs-comment'>-- </span>
<a name="line-7"></a><span class='hs-comment'>-- Maintainer : Simon Meier <iridcode@gmail.com></span>
<a name="line-8"></a><span class='hs-comment'>-- Stability : experimental</span>
<a name="line-9"></a><span class='hs-comment'>-- Portability : tested on GHC only</span>
<a name="line-10"></a><span class='hs-comment'>--</span>
<a name="line-11"></a><span class='hs-comment'>-- Core types and functions for the 'Builder' monoid and the 'Put' monad.</span>
<a name="line-12"></a><span class='hs-comment'>--</span>
<a name="line-13"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Blaze</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Builder</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span> <span class='hs-layout'>(</span>
<a name="line-14"></a>
<a name="line-15"></a> <span class='hs-comment'>-- * Build Steps</span>
<a name="line-16"></a> <span class='hs-conid'>BufRange</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-17"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>BuildSignal</span>
<a name="line-18"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>BuildStep</span>
<a name="line-19"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>done</span>
<a name="line-20"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>bufferFull</span>
<a name="line-21"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>insertByteString</span>
<a name="line-22"></a>
<a name="line-23"></a> <span class='hs-comment'>-- * Builder</span>
<a name="line-24"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Builder</span>
<a name="line-25"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fromBuildStepCont</span>
<a name="line-26"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fromPut</span>
<a name="line-27"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>flush</span>
<a name="line-28"></a>
<a name="line-29"></a> <span class='hs-comment'>-- * Put</span>
<a name="line-30"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Put</span>
<a name="line-31"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>putBuilder</span>
<a name="line-32"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>putBuildStepCont</span>
<a name="line-33"></a>
<a name="line-34"></a> <span class='hs-comment'>-- * Writes</span>
<a name="line-35"></a> <span class='hs-layout'>,</span> <span class='hs-keyword'>module</span> <span class='hs-conid'>Blaze</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Builder</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span><span class='hs-varop'>.</span><span class='hs-conid'>Write</span>
<a name="line-36"></a>
<a name="line-37"></a> <span class='hs-comment'>-- * Execution</span>
<a name="line-38"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>toLazyByteString</span>
<a name="line-39"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>toLazyByteStringWith</span>
<a name="line-40"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>toByteString</span>
<a name="line-41"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>toByteStringIO</span>
<a name="line-42"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>toByteStringIOWith</span>
<a name="line-43"></a>
<a name="line-44"></a> <span class='hs-comment'>-- * Deafult Sizes</span>
<a name="line-45"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>defaultFirstBufferSize</span>
<a name="line-46"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>defaultMinimalBufferSize</span>
<a name="line-47"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>defaultBufferSize</span>
<a name="line-48"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>defaultMaximalCopySize</span>
<a name="line-49"></a><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-50"></a>
<a name="line-51"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span>
<a name="line-52"></a>
<a name="line-53"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span> <span class='hs-layout'>(</span><span class='hs-varid'>unless</span><span class='hs-layout'>)</span>
<a name="line-54"></a>
<a name="line-55"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>S</span>
<a name="line-56"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>S</span>
<a name="line-57"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Lazy</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>L</span>
<a name="line-58"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Lazy</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>L</span>
<a name="line-59"></a>
<a name="line-60"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Blaze</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Builder</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span><span class='hs-varop'>.</span><span class='hs-conid'>Types</span>
<a name="line-61"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Blaze</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Builder</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span><span class='hs-varop'>.</span><span class='hs-conid'>Write</span>
<a name="line-62"></a>
<a name="line-63"></a><span class='hs-comment'>------------------------------------------------------------------------------</span>
<a name="line-64"></a><span class='hs-comment'>-- Internal global constants.</span>
<a name="line-65"></a><span class='hs-comment'>------------------------------------------------------------------------------</span>
<a name="line-66"></a>
<a name="line-67"></a><a name="defaultBufferSize"></a><span class='hs-comment'>-- | Default size (~32kb) for the buffer that becomes a chunk of the output</span>
<a name="line-68"></a><span class='hs-comment'>-- stream once it is filled.</span>
<a name="line-69"></a><span class='hs-comment'>--</span>
<a name="line-70"></a><span class='hs-definition'>defaultBufferSize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-71"></a><span class='hs-definition'>defaultBufferSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>32</span> <span class='hs-varop'>*</span> <span class='hs-num'>1024</span> <span class='hs-comment'>-</span> <span class='hs-varid'>overhead</span> <span class='hs-comment'>-- Copied from Data.ByteString.Lazy.</span>
<a name="line-72"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>overhead</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>2</span> <span class='hs-varop'>*</span> <span class='hs-varid'>sizeOf</span> <span class='hs-layout'>(</span><span class='hs-varid'>undefined</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span><span class='hs-layout'>)</span>
<a name="line-73"></a>
<a name="line-74"></a><a name="defaultMinimalBufferSize"></a><span class='hs-comment'>-- | The minimal length (~4kb) a buffer must have before filling it and</span>
<a name="line-75"></a><span class='hs-comment'>-- outputting it as a chunk of the output stream. </span>
<a name="line-76"></a><span class='hs-comment'>--</span>
<a name="line-77"></a><span class='hs-comment'>-- This size determines when a buffer is spilled after a 'flush' or a direct</span>
<a name="line-78"></a><span class='hs-comment'>-- bytestring insertion. It is also the size of the first chunk generated by</span>
<a name="line-79"></a><span class='hs-comment'>-- 'toLazyByteString'.</span>
<a name="line-80"></a><span class='hs-definition'>defaultMinimalBufferSize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-81"></a><span class='hs-definition'>defaultMinimalBufferSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>4</span> <span class='hs-varop'>*</span> <span class='hs-num'>1024</span> <span class='hs-comment'>-</span> <span class='hs-varid'>overhead</span>
<a name="line-82"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>overhead</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>2</span> <span class='hs-varop'>*</span> <span class='hs-varid'>sizeOf</span> <span class='hs-layout'>(</span><span class='hs-varid'>undefined</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span><span class='hs-layout'>)</span>
<a name="line-83"></a>
<a name="line-84"></a><a name="defaultFirstBufferSize"></a><span class='hs-comment'>-- | The default length (64) for the first buffer to be allocated when</span>
<a name="line-85"></a><span class='hs-comment'>-- converting a 'Builder' to a lazy bytestring. </span>
<a name="line-86"></a><span class='hs-comment'>--</span>
<a name="line-87"></a><span class='hs-comment'>-- See 'toLazyByteStringWith' for further explanation.</span>
<a name="line-88"></a><span class='hs-definition'>defaultFirstBufferSize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-89"></a><span class='hs-definition'>defaultFirstBufferSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>64</span>
<a name="line-90"></a>
<a name="line-91"></a><a name="defaultMaximalCopySize"></a><span class='hs-comment'>-- | The maximal number of bytes for that copying is cheaper than direct</span>
<a name="line-92"></a><span class='hs-comment'>-- insertion into the output stream. This takes into account the fragmentation</span>
<a name="line-93"></a><span class='hs-comment'>-- that may occur in the output buffer due to the early 'flush' implied by the</span>
<a name="line-94"></a><span class='hs-comment'>-- direct bytestring insertion.</span>
<a name="line-95"></a><span class='hs-comment'>--</span>
<a name="line-96"></a><span class='hs-comment'>-- @'defaultMaximalCopySize' = 2 * 'defaultMinimalBufferSize'@</span>
<a name="line-97"></a><span class='hs-comment'>--</span>
<a name="line-98"></a><span class='hs-definition'>defaultMaximalCopySize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-99"></a><span class='hs-definition'>defaultMaximalCopySize</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>2</span> <span class='hs-varop'>*</span> <span class='hs-varid'>defaultMinimalBufferSize</span>
<a name="line-100"></a>
<a name="line-101"></a><span class='hs-comment'>------------------------------------------------------------------------------</span>
<a name="line-102"></a><span class='hs-comment'>-- Flushing and running a Builder</span>
<a name="line-103"></a><span class='hs-comment'>------------------------------------------------------------------------------</span>
<a name="line-104"></a>
<a name="line-105"></a><a name="nonEmptyChunk"></a><span class='hs-comment'>-- | Prepend the chunk if it is non-empty.</span>
<a name="line-106"></a><span class='hs-comment'>{-# INLINE nonEmptyChunk #-}</span>
<a name="line-107"></a><span class='hs-definition'>nonEmptyChunk</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span>
<a name="line-108"></a><span class='hs-definition'>nonEmptyChunk</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>lbs</span> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>null</span> <span class='hs-varid'>bs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>lbs</span>
<a name="line-109"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>lbs</span>
<a name="line-110"></a>
<a name="line-111"></a>
<a name="line-112"></a><a name="flush"></a><span class='hs-comment'>-- | Output all data written in the current buffer and start a new chunk.</span>
<a name="line-113"></a><span class='hs-comment'>--</span>
<a name="line-114"></a><span class='hs-comment'>-- The use uf this function depends on how the resulting bytestrings are</span>
<a name="line-115"></a><span class='hs-comment'>-- consumed. 'flush' is possibly not very useful in non-interactive scenarios.</span>
<a name="line-116"></a><span class='hs-comment'>-- However, it is kept for compatibility with the builder provided by</span>
<a name="line-117"></a><span class='hs-comment'>-- Data.Binary.Builder.</span>
<a name="line-118"></a><span class='hs-comment'>--</span>
<a name="line-119"></a><span class='hs-comment'>-- When using 'toLazyByteString' to extract a lazy 'L.ByteString' from a</span>
<a name="line-120"></a><span class='hs-comment'>-- 'Builder', this means that a new chunk will be started in the resulting lazy</span>
<a name="line-121"></a><span class='hs-comment'>-- 'L.ByteString'. The remaining part of the buffer is spilled, if the</span>
<a name="line-122"></a><span class='hs-comment'>-- reamining free space is smaller than the minimal desired buffer size.</span>
<a name="line-123"></a><span class='hs-comment'>--</span>
<a name="line-124"></a><span class='hs-comment'>{-# INLINE flush #-}</span>
<a name="line-125"></a><span class='hs-definition'>flush</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Builder</span>
<a name="line-126"></a><span class='hs-definition'>flush</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromBuildStepCont</span> <span class='hs-varid'>step</span>
<a name="line-127"></a> <span class='hs-keyword'>where</span>
<a name="line-128"></a> <span class='hs-varid'>step</span> <span class='hs-varid'>k</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-conid'>BufRange</span> <span class='hs-varid'>op</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>insertByteString</span> <span class='hs-varid'>op</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>empty</span> <span class='hs-varid'>k</span>
<a name="line-129"></a>
<a name="line-130"></a><a name="toLazyByteStringWith"></a><span class='hs-comment'>-- | Run a 'Builder' with the given buffer sizes.</span>
<a name="line-131"></a><span class='hs-comment'>--</span>
<a name="line-132"></a><span class='hs-comment'>-- Use this function for integrating the 'Builder' type with other libraries</span>
<a name="line-133"></a><span class='hs-comment'>-- that generate lazy bytestrings.</span>
<a name="line-134"></a><span class='hs-comment'>--</span>
<a name="line-135"></a><span class='hs-comment'>-- Note that the builders should guarantee that on average the desired chunk</span>
<a name="line-136"></a><span class='hs-comment'>-- size is attained. Builders may decide to start a new buffer and not</span>
<a name="line-137"></a><span class='hs-comment'>-- completely fill the existing buffer, if this is faster. However, they should</span>
<a name="line-138"></a><span class='hs-comment'>-- not spill too much of the buffer, if they cannot compensate for it.</span>
<a name="line-139"></a><span class='hs-comment'>--</span>
<a name="line-140"></a><span class='hs-comment'>-- A call @toLazyByteStringWith bufSize minBufSize firstBufSize@ will generate</span>
<a name="line-141"></a><span class='hs-comment'>-- a lazy bytestring according to the following strategy. First, we allocate</span>
<a name="line-142"></a><span class='hs-comment'>-- a buffer of size @firstBufSize@ and start filling it. If it overflows, we</span>
<a name="line-143"></a><span class='hs-comment'>-- allocate a buffer of size @minBufSize@ and copy the first buffer to it in</span>
<a name="line-144"></a><span class='hs-comment'>-- order to avoid generating a too small chunk. Finally, every next buffer will</span>
<a name="line-145"></a><span class='hs-comment'>-- be of size @bufSize@. This, slow startup strategy is required to achieve</span>
<a name="line-146"></a><span class='hs-comment'>-- good speed for short (<200 bytes) resulting bytestrings, as for them the</span>
<a name="line-147"></a><span class='hs-comment'>-- allocation cost is of a large buffer cannot be compensated. Moreover, this</span>
<a name="line-148"></a><span class='hs-comment'>-- strategy also allows us to avoid spilling too much memory for short</span>
<a name="line-149"></a><span class='hs-comment'>-- resulting bytestrings.</span>
<a name="line-150"></a><span class='hs-comment'>--</span>
<a name="line-151"></a><span class='hs-comment'>-- Note that setting @firstBufSize >= minBufSize@ implies that the first buffer</span>
<a name="line-152"></a><span class='hs-comment'>-- is no longer copied but allocated and filled directly. Hence, setting</span>
<a name="line-153"></a><span class='hs-comment'>-- @firstBufSize = bufSize@ means that all chunks will use an underlying buffer</span>
<a name="line-154"></a><span class='hs-comment'>-- of size @bufSize@. This is recommended, if you know that you always output</span>
<a name="line-155"></a><span class='hs-comment'>-- more than @minBufSize@ bytes.</span>
<a name="line-156"></a><span class='hs-definition'>toLazyByteStringWith</span>
<a name="line-157"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ Buffer size (upper-bounds the resulting chunk size).</span>
<a name="line-158"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ Minimal free buffer space for continuing filling</span>
<a name="line-159"></a> <span class='hs-comment'>-- the same buffer after a 'flush' or a direct bytestring</span>
<a name="line-160"></a> <span class='hs-comment'>-- insertion. This corresponds to the minimal desired</span>
<a name="line-161"></a> <span class='hs-comment'>-- chunk size.</span>
<a name="line-162"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ Size of the first buffer to be used and copied for</span>
<a name="line-163"></a> <span class='hs-comment'>-- larger resulting sequences</span>
<a name="line-164"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Builder</span> <span class='hs-comment'>-- ^ Builder to run.</span>
<a name="line-165"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-comment'>-- ^ Lazy bytestring to output after the builder is</span>
<a name="line-166"></a> <span class='hs-comment'>-- finished.</span>
<a name="line-167"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-comment'>-- ^ Resulting lazy bytestring</span>
<a name="line-168"></a><span class='hs-definition'>toLazyByteStringWith</span> <span class='hs-varid'>bufSize</span> <span class='hs-varid'>minBufSize</span> <span class='hs-varid'>firstBufSize</span> <span class='hs-layout'>(</span><span class='hs-conid'>Builder</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-varid'>k</span> <span class='hs-keyglyph'>=</span>
<a name="line-169"></a> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>inlinePerformIO</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fillFirstBuffer</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-varid'>buildStep</span> <span class='hs-varid'>finalStep</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-170"></a> <span class='hs-keyword'>where</span>
<a name="line-171"></a> <span class='hs-varid'>finalStep</span> <span class='hs-layout'>(</span><span class='hs-conid'>BufRange</span> <span class='hs-varid'>pf</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Done</span> <span class='hs-varid'>pf</span> <span class='hs-conid'>()</span>
<a name="line-172"></a> <span class='hs-comment'>-- fill a first very small buffer, if we need more space then copy it</span>
<a name="line-173"></a> <span class='hs-comment'>-- to the new buffer of size 'minBufSize'. This way we don't pay the</span>
<a name="line-174"></a> <span class='hs-comment'>-- allocation cost of the big 'bufSize' buffer, when outputting only</span>
<a name="line-175"></a> <span class='hs-comment'>-- small sequences.</span>
<a name="line-176"></a> <span class='hs-varid'>fillFirstBuffer</span> <span class='hs-varop'>!</span><span class='hs-varid'>step0</span>
<a name="line-177"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>minBufSize</span> <span class='hs-varop'><=</span> <span class='hs-varid'>firstBufSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fillNewBuffer</span> <span class='hs-varid'>firstBufSize</span> <span class='hs-varid'>step0</span>
<a name="line-178"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-179"></a> <span class='hs-varid'>fpbuf</span> <span class='hs-keyglyph'><-</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>mallocByteString</span> <span class='hs-varid'>firstBufSize</span>
<a name="line-180"></a> <span class='hs-varid'>withForeignPtr</span> <span class='hs-varid'>fpbuf</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>pf</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-181"></a> <span class='hs-keyword'>let</span> <span class='hs-varop'>!</span><span class='hs-varid'>pe</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>pf</span> <span class='hs-varop'>`plusPtr`</span> <span class='hs-varid'>firstBufSize</span>
<a name="line-182"></a> <span class='hs-varid'>mkbs</span> <span class='hs-varid'>pf'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>PS</span> <span class='hs-varid'>fpbuf</span> <span class='hs-num'>0</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf'</span> <span class='hs-varop'>`minusPtr`</span> <span class='hs-varid'>pf</span><span class='hs-layout'>)</span>
<a name="line-183"></a> <span class='hs-comment'>{-# INLINE mkbs #-}</span>
<a name="line-184"></a> <span class='hs-varid'>next</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>runBuildStep</span> <span class='hs-varid'>step0</span> <span class='hs-layout'>(</span><span class='hs-conid'>BufRange</span> <span class='hs-varid'>pf</span> <span class='hs-varid'>pe</span><span class='hs-layout'>)</span>
<a name="line-185"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>next</span> <span class='hs-keyword'>of</span>
<a name="line-186"></a> <span class='hs-conid'>Done</span> <span class='hs-varid'>pf'</span> <span class='hs-keyword'>_</span>
<a name="line-187"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>pf'</span> <span class='hs-varop'>==</span> <span class='hs-varid'>pf</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varid'>k</span>
<a name="line-188"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Chunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>mkbs</span> <span class='hs-varid'>pf'</span><span class='hs-layout'>)</span> <span class='hs-varid'>k</span>
<a name="line-189"></a>
<a name="line-190"></a> <span class='hs-conid'>BufferFull</span> <span class='hs-varid'>newSize</span> <span class='hs-varid'>pf'</span> <span class='hs-varid'>nextStep</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-191"></a> <span class='hs-keyword'>let</span> <span class='hs-varop'>!</span><span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>pf'</span> <span class='hs-varop'>`minusPtr`</span> <span class='hs-varid'>pf</span>
<a name="line-192"></a> <span class='hs-varid'>fillNewBuffer</span> <span class='hs-layout'>(</span><span class='hs-varid'>max</span> <span class='hs-layout'>(</span><span class='hs-varid'>l</span> <span class='hs-varop'>+</span> <span class='hs-varid'>newSize</span><span class='hs-layout'>)</span> <span class='hs-varid'>minBufSize</span><span class='hs-layout'>)</span> <span class='hs-varop'>$</span> <span class='hs-varid'>buildStep</span> <span class='hs-varop'>$</span>
<a name="line-193"></a> <span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-conid'>BufRange</span> <span class='hs-varid'>pfNew</span> <span class='hs-varid'>peNew</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-194"></a> <span class='hs-varid'>copyBytes</span> <span class='hs-varid'>pfNew</span> <span class='hs-varid'>pf</span> <span class='hs-varid'>l</span>
<a name="line-195"></a> <span class='hs-keyword'>let</span> <span class='hs-varop'>!</span><span class='hs-varid'>br'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BufRange</span> <span class='hs-layout'>(</span><span class='hs-varid'>pfNew</span> <span class='hs-varop'>`plusPtr`</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-varid'>peNew</span>
<a name="line-196"></a> <span class='hs-varid'>runBuildStep</span> <span class='hs-varid'>nextStep</span> <span class='hs-varid'>br'</span>
<a name="line-197"></a>
<a name="line-198"></a> <span class='hs-conid'>InsertByteString</span> <span class='hs-varid'>pf'</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>nextStep</span>
<a name="line-199"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>pf'</span> <span class='hs-varop'>==</span> <span class='hs-varid'>pf</span> <span class='hs-keyglyph'>-></span>
<a name="line-200"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>nonEmptyChunk</span> <span class='hs-varid'>bs</span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>inlinePerformIO</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fillNewBuffer</span> <span class='hs-varid'>bufSize</span> <span class='hs-varid'>nextStep</span><span class='hs-layout'>)</span>
<a name="line-201"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span>
<a name="line-202"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Chunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>mkbs</span> <span class='hs-varid'>pf'</span><span class='hs-layout'>)</span>
<a name="line-203"></a> <span class='hs-layout'>(</span><span class='hs-varid'>nonEmptyChunk</span> <span class='hs-varid'>bs</span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>inlinePerformIO</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fillNewBuffer</span> <span class='hs-varid'>bufSize</span> <span class='hs-varid'>nextStep</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-204"></a>
<a name="line-205"></a> <span class='hs-comment'>-- allocate and fill a new buffer</span>
<a name="line-206"></a> <span class='hs-varid'>fillNewBuffer</span> <span class='hs-varop'>!</span><span class='hs-varid'>size</span> <span class='hs-varop'>!</span><span class='hs-varid'>step0</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-207"></a> <span class='hs-varid'>fpbuf</span> <span class='hs-keyglyph'><-</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>mallocByteString</span> <span class='hs-varid'>size</span>
<a name="line-208"></a> <span class='hs-varid'>withForeignPtr</span> <span class='hs-varid'>fpbuf</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fillBuffer</span> <span class='hs-varid'>fpbuf</span>
<a name="line-209"></a> <span class='hs-keyword'>where</span>
<a name="line-210"></a> <span class='hs-varid'>fillBuffer</span> <span class='hs-varid'>fpbuf</span> <span class='hs-varop'>!</span><span class='hs-varid'>pbuf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fill</span> <span class='hs-varid'>pbuf</span> <span class='hs-varid'>step0</span>
<a name="line-211"></a> <span class='hs-keyword'>where</span>
<a name="line-212"></a> <span class='hs-varop'>!</span><span class='hs-varid'>pe</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>pbuf</span> <span class='hs-varop'>`plusPtr`</span> <span class='hs-varid'>size</span>
<a name="line-213"></a> <span class='hs-varid'>fill</span> <span class='hs-varop'>!</span><span class='hs-varid'>pf</span> <span class='hs-varop'>!</span><span class='hs-varid'>step</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-214"></a> <span class='hs-varid'>next</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>runBuildStep</span> <span class='hs-varid'>step</span> <span class='hs-layout'>(</span><span class='hs-conid'>BufRange</span> <span class='hs-varid'>pf</span> <span class='hs-varid'>pe</span><span class='hs-layout'>)</span>
<a name="line-215"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>mkbs</span> <span class='hs-varid'>pf'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>PS</span> <span class='hs-varid'>fpbuf</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf</span> <span class='hs-varop'>`minusPtr`</span> <span class='hs-varid'>pbuf</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf'</span> <span class='hs-varop'>`minusPtr`</span> <span class='hs-varid'>pf</span><span class='hs-layout'>)</span>
<a name="line-216"></a> <span class='hs-comment'>{-# INLINE mkbs #-}</span>
<a name="line-217"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>next</span> <span class='hs-keyword'>of</span>
<a name="line-218"></a> <span class='hs-conid'>Done</span> <span class='hs-varid'>pf'</span> <span class='hs-keyword'>_</span>
<a name="line-219"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>pf'</span> <span class='hs-varop'>==</span> <span class='hs-varid'>pf</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varid'>k</span>
<a name="line-220"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Chunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>mkbs</span> <span class='hs-varid'>pf'</span><span class='hs-layout'>)</span> <span class='hs-varid'>k</span>
<a name="line-221"></a>
<a name="line-222"></a> <span class='hs-conid'>BufferFull</span> <span class='hs-varid'>newSize</span> <span class='hs-varid'>pf'</span> <span class='hs-varid'>nextStep</span>
<a name="line-223"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>pf'</span> <span class='hs-varop'>==</span> <span class='hs-varid'>pf</span> <span class='hs-keyglyph'>-></span>
<a name="line-224"></a> <span class='hs-varid'>fillNewBuffer</span> <span class='hs-layout'>(</span><span class='hs-varid'>max</span> <span class='hs-varid'>newSize</span> <span class='hs-varid'>bufSize</span><span class='hs-layout'>)</span> <span class='hs-varid'>nextStep</span>
<a name="line-225"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span>
<a name="line-226"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Chunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>mkbs</span> <span class='hs-varid'>pf'</span><span class='hs-layout'>)</span>
<a name="line-227"></a> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>inlinePerformIO</span> <span class='hs-varop'>$</span>
<a name="line-228"></a> <span class='hs-varid'>fillNewBuffer</span> <span class='hs-layout'>(</span><span class='hs-varid'>max</span> <span class='hs-varid'>newSize</span> <span class='hs-varid'>bufSize</span><span class='hs-layout'>)</span> <span class='hs-varid'>nextStep</span><span class='hs-layout'>)</span>
<a name="line-229"></a>
<a name="line-230"></a> <span class='hs-conid'>InsertByteString</span> <span class='hs-varid'>pf'</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>nextStep</span>
<a name="line-231"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>pf'</span> <span class='hs-varop'>==</span> <span class='hs-varid'>pf</span> <span class='hs-keyglyph'>-></span>
<a name="line-232"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>nonEmptyChunk</span> <span class='hs-varid'>bs</span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>inlinePerformIO</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fill</span> <span class='hs-varid'>pf'</span> <span class='hs-varid'>nextStep</span><span class='hs-layout'>)</span>
<a name="line-233"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>minBufSize</span> <span class='hs-varop'><</span> <span class='hs-varid'>pe</span> <span class='hs-varop'>`minusPtr`</span> <span class='hs-varid'>pf'</span> <span class='hs-keyglyph'>-></span>
<a name="line-234"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Chunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>mkbs</span> <span class='hs-varid'>pf'</span><span class='hs-layout'>)</span>
<a name="line-235"></a> <span class='hs-layout'>(</span><span class='hs-varid'>nonEmptyChunk</span> <span class='hs-varid'>bs</span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>inlinePerformIO</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fill</span> <span class='hs-varid'>pf'</span> <span class='hs-varid'>nextStep</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-236"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span>
<a name="line-237"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Chunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>mkbs</span> <span class='hs-varid'>pf'</span><span class='hs-layout'>)</span>
<a name="line-238"></a> <span class='hs-layout'>(</span><span class='hs-varid'>nonEmptyChunk</span> <span class='hs-varid'>bs</span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>inlinePerformIO</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fillNewBuffer</span> <span class='hs-varid'>bufSize</span> <span class='hs-varid'>nextStep</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-239"></a>
<a name="line-240"></a>
<a name="line-241"></a><a name="toLazyByteString"></a><span class='hs-comment'>-- | Extract the lazy 'L.ByteString' from the builder by running it with default</span>
<a name="line-242"></a><span class='hs-comment'>-- buffer sizes. Use this function, if you do not have any special</span>
<a name="line-243"></a><span class='hs-comment'>-- considerations with respect to buffer sizes.</span>
<a name="line-244"></a><span class='hs-comment'>--</span>
<a name="line-245"></a><span class='hs-comment'>-- @ 'toLazyByteString' b = 'toLazyByteStringWith' 'defaultBufferSize' 'defaultMinimalBufferSize' 'defaultFirstBufferSize' b L.empty@</span>
<a name="line-246"></a><span class='hs-comment'>--</span>
<a name="line-247"></a><span class='hs-comment'>-- Note that @'toLazyByteString'@ is a 'Monoid' homomorphism.</span>
<a name="line-248"></a><span class='hs-comment'>--</span>
<a name="line-249"></a><span class='hs-comment'>-- > toLazyByteString mempty == mempty</span>
<a name="line-250"></a><span class='hs-comment'>-- > toLazyByteString (x `mappend` y) == toLazyByteString x `mappend` toLazyByteString y</span>
<a name="line-251"></a><span class='hs-comment'>--</span>
<a name="line-252"></a><span class='hs-comment'>-- However, in the second equation, the left-hand-side is generally faster to</span>
<a name="line-253"></a><span class='hs-comment'>-- execute.</span>
<a name="line-254"></a><span class='hs-comment'>--</span>
<a name="line-255"></a><span class='hs-definition'>toLazyByteString</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Builder</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span>
<a name="line-256"></a><span class='hs-definition'>toLazyByteString</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>toLazyByteStringWith</span>
<a name="line-257"></a> <span class='hs-varid'>defaultBufferSize</span> <span class='hs-varid'>defaultMinimalBufferSize</span> <span class='hs-varid'>defaultFirstBufferSize</span> <span class='hs-varid'>b</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-varid'>empty</span>
<a name="line-258"></a><span class='hs-comment'>{-# INLINE toLazyByteString #-}</span>
<a name="line-259"></a>
<a name="line-260"></a><a name="packChunks"></a><span class='hs-comment'>-- | Pack the chunks of a lazy bytestring into a single strict bytestring.</span>
<a name="line-261"></a><span class='hs-definition'>packChunks</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span>
<a name="line-262"></a><span class='hs-definition'>packChunks</span> <span class='hs-varid'>lbs</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-263"></a> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>unsafeCreate</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varop'>$</span> <span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-varid'>length</span> <span class='hs-varid'>lbs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>copyChunks</span> <span class='hs-varid'>lbs</span><span class='hs-layout'>)</span>
<a name="line-264"></a> <span class='hs-keyword'>where</span>
<a name="line-265"></a> <span class='hs-varid'>copyChunks</span> <span class='hs-varop'>!</span><span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Empty</span> <span class='hs-varop'>!</span><span class='hs-sel'>_pf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-266"></a> <span class='hs-varid'>copyChunks</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-conid'>L</span><span class='hs-varop'>.</span><span class='hs-conid'>Chunk</span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>PS</span> <span class='hs-varid'>fpbuf</span> <span class='hs-varid'>o</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-varid'>lbs'</span><span class='hs-layout'>)</span> <span class='hs-varop'>!</span><span class='hs-varid'>pf</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-267"></a> <span class='hs-varid'>withForeignPtr</span> <span class='hs-varid'>fpbuf</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>pbuf</span> <span class='hs-keyglyph'>-></span>
<a name="line-268"></a> <span class='hs-varid'>copyBytes</span> <span class='hs-varid'>pf</span> <span class='hs-layout'>(</span><span class='hs-varid'>pbuf</span> <span class='hs-varop'>`plusPtr`</span> <span class='hs-varid'>o</span><span class='hs-layout'>)</span> <span class='hs-varid'>l</span>
<a name="line-269"></a> <span class='hs-varid'>copyChunks</span> <span class='hs-varid'>lbs'</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf</span> <span class='hs-varop'>`plusPtr`</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span>
<a name="line-270"></a>
<a name="line-271"></a><a name="toByteString"></a><span class='hs-comment'>-- | Run the builder to construct a strict bytestring containing the sequence</span>
<a name="line-272"></a><span class='hs-comment'>-- of bytes denoted by the builder. This is done by first serializing to a lazy bytestring and then packing its</span>
<a name="line-273"></a><span class='hs-comment'>-- chunks to a appropriately sized strict bytestring.</span>
<a name="line-274"></a><span class='hs-comment'>--</span>
<a name="line-275"></a><span class='hs-comment'>-- > toByteString = packChunks . toLazyByteString</span>
<a name="line-276"></a><span class='hs-comment'>--</span>
<a name="line-277"></a><span class='hs-comment'>-- Note that @'toByteString'@ is a 'Monoid' homomorphism.</span>
<a name="line-278"></a><span class='hs-comment'>--</span>
<a name="line-279"></a><span class='hs-comment'>-- > toByteString mempty == mempty</span>
<a name="line-280"></a><span class='hs-comment'>-- > toByteString (x `mappend` y) == toByteString x `mappend` toByteString y</span>
<a name="line-281"></a><span class='hs-comment'>--</span>
<a name="line-282"></a><span class='hs-comment'>-- However, in the second equation, the left-hand-side is generally faster to</span>
<a name="line-283"></a><span class='hs-comment'>-- execute.</span>
<a name="line-284"></a><span class='hs-comment'>--</span>
<a name="line-285"></a><span class='hs-definition'>toByteString</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Builder</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span>
<a name="line-286"></a><span class='hs-definition'>toByteString</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>packChunks</span> <span class='hs-varop'>.</span> <span class='hs-varid'>toLazyByteString</span>
<a name="line-287"></a>
<a name="line-288"></a>
<a name="line-289"></a><a name="toByteStringIOWith"></a><span class='hs-comment'>-- | @toByteStringIOWith bufSize io b@ runs the builder @b@ with a buffer of</span>
<a name="line-290"></a><span class='hs-comment'>-- at least the size @bufSize@ and executes the 'IO' action @io@ whenever the</span>
<a name="line-291"></a><span class='hs-comment'>-- buffer is full.</span>
<a name="line-292"></a><span class='hs-comment'>--</span>
<a name="line-293"></a><span class='hs-comment'>-- Compared to 'toLazyByteStringWith' this function requires less allocation,</span>
<a name="line-294"></a><span class='hs-comment'>-- as the output buffer is only allocated once at the start of the</span>
<a name="line-295"></a><span class='hs-comment'>-- serialization and whenever something bigger than the current buffer size has</span>
<a name="line-296"></a><span class='hs-comment'>-- to be copied into the buffer, which should happen very seldomly for the</span>
<a name="line-297"></a><span class='hs-comment'>-- default buffer size of 32kb. Hence, the pressure on the garbage collector is</span>
<a name="line-298"></a><span class='hs-comment'>-- reduced, which can be an advantage when building long sequences of bytes.</span>
<a name="line-299"></a><span class='hs-comment'>--</span>
<a name="line-300"></a><span class='hs-definition'>toByteStringIOWith</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ Buffer size (upper bounds</span>
<a name="line-301"></a> <span class='hs-comment'>-- the number of bytes forced</span>
<a name="line-302"></a> <span class='hs-comment'>-- per call to the 'IO' action).</span>
<a name="line-303"></a> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ 'IO' action to execute per</span>
<a name="line-304"></a> <span class='hs-comment'>-- full buffer, which is</span>
<a name="line-305"></a> <span class='hs-comment'>-- referenced by a strict</span>
<a name="line-306"></a> <span class='hs-comment'>-- 'S.ByteString'.</span>
<a name="line-307"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Builder</span> <span class='hs-comment'>-- ^ 'Builder' to run.</span>
<a name="line-308"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span> <span class='hs-comment'>-- ^ Resulting 'IO' action.</span>
<a name="line-309"></a><span class='hs-definition'>toByteStringIOWith</span> <span class='hs-varid'>bufSize</span> <span class='hs-varid'>io</span> <span class='hs-layout'>(</span><span class='hs-conid'>Builder</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-310"></a> <span class='hs-varid'>fillBuffer</span> <span class='hs-varid'>bufSize</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-varid'>buildStep</span> <span class='hs-varid'>finalStep</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-311"></a> <span class='hs-keyword'>where</span>
<a name="line-312"></a> <span class='hs-varid'>finalStep</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-conid'>BufRange</span> <span class='hs-varid'>pf</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Done</span> <span class='hs-varid'>pf</span> <span class='hs-conid'>()</span>
<a name="line-313"></a>
<a name="line-314"></a> <span class='hs-varid'>fillBuffer</span> <span class='hs-varop'>!</span><span class='hs-varid'>size</span> <span class='hs-varid'>step</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-315"></a> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>mallocByteString</span> <span class='hs-varid'>size</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>fill</span>
<a name="line-316"></a> <span class='hs-keyword'>where</span>
<a name="line-317"></a> <span class='hs-varid'>fill</span> <span class='hs-varid'>fpbuf</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-318"></a> <span class='hs-keyword'>let</span> <span class='hs-varop'>!</span><span class='hs-varid'>pf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>unsafeForeignPtrToPtr</span> <span class='hs-varid'>fpbuf</span>
<a name="line-319"></a> <span class='hs-varop'>!</span><span class='hs-varid'>br</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BufRange</span> <span class='hs-varid'>pf</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf</span> <span class='hs-varop'>`plusPtr`</span> <span class='hs-varid'>size</span><span class='hs-layout'>)</span>
<a name="line-320"></a> <span class='hs-comment'>-- safe due to later reference of fpbuf</span>
<a name="line-321"></a> <span class='hs-comment'>-- BETTER than withForeignPtr, as we lose a tail call otherwise</span>
<a name="line-322"></a> <span class='hs-varid'>signal</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>runBuildStep</span> <span class='hs-varid'>step</span> <span class='hs-varid'>br</span>
<a name="line-323"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>signal</span> <span class='hs-keyword'>of</span>
<a name="line-324"></a> <span class='hs-conid'>Done</span> <span class='hs-varid'>pf'</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>io</span> <span class='hs-varop'>$</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>PS</span> <span class='hs-varid'>fpbuf</span> <span class='hs-num'>0</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf'</span> <span class='hs-varop'>`minusPtr`</span> <span class='hs-varid'>pf</span><span class='hs-layout'>)</span>
<a name="line-325"></a>
<a name="line-326"></a> <span class='hs-conid'>BufferFull</span> <span class='hs-varid'>minSize</span> <span class='hs-varid'>pf'</span> <span class='hs-varid'>nextStep</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-327"></a> <span class='hs-varid'>io</span> <span class='hs-varop'>$</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>PS</span> <span class='hs-varid'>fpbuf</span> <span class='hs-num'>0</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf'</span> <span class='hs-varop'>`minusPtr`</span> <span class='hs-varid'>pf</span><span class='hs-layout'>)</span>
<a name="line-328"></a> <span class='hs-varid'>fillBuffer</span> <span class='hs-layout'>(</span><span class='hs-varid'>max</span> <span class='hs-varid'>bufSize</span> <span class='hs-varid'>minSize</span><span class='hs-layout'>)</span> <span class='hs-varid'>nextStep</span>
<a name="line-329"></a>
<a name="line-330"></a> <span class='hs-conid'>InsertByteString</span> <span class='hs-varid'>pf'</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>nextStep</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-331"></a> <span class='hs-varid'>io</span> <span class='hs-varop'>$</span> <span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>PS</span> <span class='hs-varid'>fpbuf</span> <span class='hs-num'>0</span> <span class='hs-layout'>(</span><span class='hs-varid'>pf'</span> <span class='hs-varop'>`minusPtr`</span> <span class='hs-varid'>pf</span><span class='hs-layout'>)</span>
<a name="line-332"></a> <span class='hs-varid'>unless</span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-varid'>null</span> <span class='hs-varid'>bs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>io</span> <span class='hs-varid'>bs</span><span class='hs-layout'>)</span>
<a name="line-333"></a> <span class='hs-varid'>fillBuffer</span> <span class='hs-varid'>bufSize</span> <span class='hs-varid'>nextStep</span>
<a name="line-334"></a>
<a name="line-335"></a><a name="toByteStringIO"></a><span class='hs-comment'>-- | Run the builder with a 'defaultBufferSize'd buffer and execute the given</span>
<a name="line-336"></a><span class='hs-comment'>-- 'IO' action whenever the buffer is full or gets flushed.</span>
<a name="line-337"></a><span class='hs-comment'>--</span>
<a name="line-338"></a><span class='hs-comment'>-- @ 'toByteStringIO' = 'toByteStringIOWith' 'defaultBufferSize'@</span>
<a name="line-339"></a><span class='hs-comment'>--</span>
<a name="line-340"></a><span class='hs-comment'>-- This is a 'Monoid' homomorphism in the following sense.</span>
<a name="line-341"></a><span class='hs-comment'>--</span>
<a name="line-342"></a><span class='hs-comment'>-- > toByteStringIO io mempty == return ()</span>
<a name="line-343"></a><span class='hs-comment'>-- > toByteStringIO io (x `mappend` y) == toByteStringIO io x >> toByteStringIO io y</span>
<a name="line-344"></a><span class='hs-comment'>--</span>
<a name="line-345"></a><span class='hs-definition'>toByteStringIO</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>S</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Builder</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-346"></a><span class='hs-definition'>toByteStringIO</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>toByteStringIOWith</span> <span class='hs-varid'>defaultBufferSize</span>
<a name="line-347"></a><span class='hs-comment'>{-# INLINE toByteStringIO #-}</span>
<a name="line-348"></a>
<a name="line-349"></a>
<a name="line-350"></a><span class='hs-comment'>------------------------------------------------------------------------------</span>
<a name="line-351"></a><span class='hs-comment'>-- Draft of new builder/put execution code</span>
<a name="line-352"></a><span class='hs-comment'>------------------------------------------------------------------------------</span>
<a name="line-353"></a>
<a name="line-354"></a><span class='hs-comment'>{- FIXME: Generalize this code such that it can replace the above clunky
<a name="line-355"></a> - implementations.
<a name="line-356"></a>
<a name="line-357"></a>-- | A monad for lazily composing lazy bytestrings using continuations.
<a name="line-358"></a>newtype LBSM a = LBSM { unLBSM :: (a, L.ByteString -> L.ByteString) }
<a name="line-359"></a>
<a name="line-360"></a>instance Monad LBSM where
<a name="line-361"></a> return x = LBSM (x, id)
<a name="line-362"></a> (LBSM (x,k)) >>= f = let LBSM (x',k') = f x in LBSM (x', k . k')
<a name="line-363"></a> (LBSM (_,k)) >> (LBSM (x',k')) = LBSM (x', k . k')
<a name="line-364"></a>
<a name="line-365"></a>-- | Execute a put and return the written buffers as the chunks of a lazy
<a name="line-366"></a>-- bytestring.
<a name="line-367"></a>toLazyByteString :: Put a -> (a, L.ByteString)
<a name="line-368"></a>toLazyByteString put =
<a name="line-369"></a> (fst result, k (bufToLBSCont (snd result) L.empty))
<a name="line-370"></a> where
<a name="line-371"></a>
<a name="line-372"></a> -- FIXME: Check with ByteString guys why allocation in inlinePerformIO is
<a name="line-373"></a> -- bad.
<a name="line-374"></a>
<a name="line-375"></a> -- initial buffer
<a name="line-376"></a> buf0 = S.inlinePerformIO $ allocBuffer defaultBufferSize
<a name="line-377"></a> -- run put, but don't force result => we're lazy enough
<a name="line-378"></a> LBSM (result, k) = runPut liftIO outputBuf outputBS put buf0
<a name="line-379"></a> -- convert a buffer to a lazy bytestring continuation
<a name="line-380"></a> bufToLBSCont = maybe id L.Chunk . unsafeFreezeNonEmptyBuffer
<a name="line-381"></a> -- lifting an io putsignal to a lazy bytestring monad
<a name="line-382"></a> liftIO io = LBSM (S.inlinePerformIO io, id)
<a name="line-383"></a> -- add buffer as a chunk prepare allocation of new one
<a name="line-384"></a> outputBuf minSize buf = LBSM
<a name="line-385"></a> ( S.inlinePerformIO $ allocBuffer (max minSize defaultBufferSize)
<a name="line-386"></a> , bufToLBSCont buf )
<a name="line-387"></a> -- add bytestring directly as a chunk; exploits postcondition of runPut
<a name="line-388"></a> -- that bytestrings are non-empty
<a name="line-389"></a> outputBS bs = LBSM ((), L.Chunk bs)
<a name="line-390"></a>
<a name="line-391"></a>
<a name="line-392"></a>{-
<a name="line-393"></a>-- | A Builder that traces a message
<a name="line-394"></a>traceBuilder :: String -> Builder
<a name="line-395"></a>traceBuilder msg = fromBuildStepCont $ \k br@(BufRange op ope) -> do
<a name="line-396"></a> putStrLn $ "traceBuilder " ++ show (op, ope) ++ ": " ++ msg
<a name="line-397"></a> k br
<a name="line-398"></a>
<a name="line-399"></a>test2 :: Word8 -> [S.ByteString]
<a name="line-400"></a>test2 x = L.toChunks $ toLazyByteString2 $ fromBuilder $ mconcat
<a name="line-401"></a> [ traceBuilder "before flush"
<a name="line-402"></a> , fromWord8 48
<a name="line-403"></a> , flushBuilder
<a name="line-404"></a> , flushBuilder
<a name="line-405"></a> , traceBuilder "after flush"
<a name="line-406"></a> , fromWord8 x
<a name="line-407"></a> ]
<a name="line-408"></a>
<a name="line-409"></a>-}
<a name="line-410"></a>
<a name="line-411"></a>-}</span>
</pre></body>
</html>
