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Subject[PATCH 1/3] bzip2/lzma/gzip: Fix comments describing decompressor API
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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 <phillip@lougher.demon.co.uk>
---
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 <linux/decompress/mm.h>
#include <linux/slab.h>

-#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");
--
1.6.1.2


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