From daeb6b6fbe27049f465c48a7d0ee5555c3b84064 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Thu, 6 Aug 2009 15:09:30 -0700 Subject: [PATCH] bzip2/lzma/gzip: fix comments describing decompressor API Fix and improve comments in decompress/generic.h that describe the decompressor API. Also remove an unused definition, and rename INBUF_LEN in lib/decompress_inflate.c to conform to bzip2/lzma naming. Signed-off-by: Phillip Lougher Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/decompress/generic.h | 32 +++++++++++++++++++------------- lib/decompress_inflate.c | 8 ++++---- 2 files changed, 23 insertions(+), 17 deletions(-) diff --git a/include/linux/decompress/generic.h b/include/linux/decompress/generic.h index 6dfb856..0c7111a 100644 --- a/include/linux/decompress/generic.h +++ b/include/linux/decompress/generic.h @@ -1,31 +1,37 @@ #ifndef DECOMPRESS_GENERIC_H #define DECOMPRESS_GENERIC_H -/* Minimal chunksize to be read. - *Bzip2 prefers at least 4096 - *Lzma prefers 0x10000 */ -#define COMPR_IOBUF_SIZE 4096 - typedef int (*decompress_fn) (unsigned char *inbuf, int len, int(*fill)(void*, unsigned int), - int(*writebb)(void*, unsigned int), - unsigned char *output, + int(*flush)(void*, unsigned int), + unsigned char *outbuf, int *posp, void(*error)(char *x)); /* inbuf - input buffer *len - len of pre-read data in inbuf - *fill - function to fill inbuf if empty - *writebb - function to write out outbug + *fill - function to fill inbuf when empty + *flush - function to write out outbuf + *outbuf - output buffer *posp - if non-null, input position (number of bytes read) will be * returned here * - *If len != 0, the inbuf is initialized (with as much data), and fill - *should not be called - *If len = 0, the inbuf is allocated, but empty. Its size is IOBUF_SIZE - *fill should be called (repeatedly...) to read data, at most IOBUF_SIZE + *If len != 0, inbuf should contain all the necessary input data, and fill + *should be NULL + *If len = 0, inbuf can be NULL, in which case the decompressor will allocate + *the input buffer. If inbuf != NULL it must be at least XXX_IOBUF_SIZE bytes. + *fill will be called (repeatedly...) to read data, at most XXX_IOBUF_SIZE + *bytes should be read per call. Replace XXX with the appropriate decompressor + *name, i.e. LZMA_IOBUF_SIZE. + * + *If flush = NULL, outbuf must be large enough to buffer all the expected + *output. If flush != NULL, the output buffer will be allocated by the + *decompressor (outbuf = NULL), and the flush function will be called to + *flush the output buffer at the appropriate time (decompressor and stream + *dependent). */ + /* Utility routine to detect the decompression method */ decompress_fn decompress_method(const unsigned char *inbuf, int len, const char **name); diff --git a/lib/decompress_inflate.c b/lib/decompress_inflate.c index e36b296..bfe605a 100644 --- a/lib/decompress_inflate.c +++ b/lib/decompress_inflate.c @@ -25,7 +25,7 @@ #include #include -#define INBUF_LEN (16*1024) +#define GZIP_IOBUF_SIZE (16*1024) /* Included from initramfs et al code */ STATIC int INIT gunzip(unsigned char *buf, int len, @@ -55,7 +55,7 @@ STATIC int INIT gunzip(unsigned char *buf, int len, if (buf) zbuf = buf; else { - zbuf = malloc(INBUF_LEN); + zbuf = malloc(GZIP_IOBUF_SIZE); len = 0; } if (!zbuf) { @@ -77,7 +77,7 @@ STATIC int INIT gunzip(unsigned char *buf, int len, } if (len == 0) - len = fill(zbuf, INBUF_LEN); + len = fill(zbuf, GZIP_IOBUF_SIZE); /* verify the gzip header */ if (len < 10 || @@ -113,7 +113,7 @@ STATIC int INIT gunzip(unsigned char *buf, int len, while (rc == Z_OK) { if (strm->avail_in == 0) { /* TODO: handle case where both pos and fill are set */ - len = fill(zbuf, INBUF_LEN); + len = fill(zbuf, GZIP_IOBUF_SIZE); if (len < 0) { rc = -1; error("read error"); -- 1.8.2.3