From 4c797d57d0ce45532e1fd3dc144ba271f2f5f86c Mon Sep 17 00:00:00 2001
From: Willem Jan Palenstijn
Date: Tue, 21 Jul 2009 09:39:58 +0000
Subject: Use a BufferedReadStream to buffer ArjFile's input to reduce memory
 usage

svn-id: r42637
---
 common/unarj.cpp | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/common/unarj.cpp b/common/unarj.cpp
index 428b4a426e..0312cc5b08 100644
--- a/common/unarj.cpp
+++ b/common/unarj.cpp
@@ -105,7 +105,7 @@ public:
 	void decode(int32 origsize);
 	void decode_f(int32 origsize);
 
-	MemoryReadStream *_compressed;
+	BufferedReadStream *_compressed;
 	MemoryWriteStream *_outstream;
 
 //protected:
@@ -360,6 +360,9 @@ bool ArjFile::open(const Common::String &filename) {
 		return false;
 
 	ArjHeader *hdr = _headers[_fileMap[filename]];
+
+	// TODO: It would be good if ArjFile could decompress files in a streaming
+	// mode, so it would not need to pre-allocate the entire output.
 	byte *uncompressedData = (byte *)malloc(hdr->origSize);
 
 	File archiveFile;
@@ -372,10 +375,11 @@ bool ArjFile::open(const Common::String &filename) {
 	} else {
 		ArjDecoder *decoder = new ArjDecoder(hdr);
 
-		byte *compressedData = (byte *)malloc(hdr->compSize);
-		archiveFile.read(compressedData, hdr->compSize);
-
-		decoder->_compressed = new MemoryReadStream(compressedData, hdr->compSize, true);
+		// TODO: It might not be appropriate to use this wrapper inside ArjFile.
+		// If reading from archiveFile directly is too slow to be usable,
+		// maybe the filesystem code should instead wrap its files
+		// in a BufferedReadStream.
+		decoder->_compressed = new BufferedReadStream(&archiveFile, 4096, false);
 		decoder->_outstream = new MemoryWriteStream(uncompressedData, hdr->origSize);
 
 		if (hdr->method == 1 || hdr->method == 2 || hdr->method == 3)
-- 
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