Commit 6155e06b74c7eaeac6dfdc32e0d71f212be32f42
2017-12-17T18:44:02
zstream: introduce a single chunk reader Introduce `get_output_chunk` that will inflate/deflate all the available input buffer into the output buffer. `get_output` will call `get_output_chunk` in a loop, while other consumers can use it to inflate only a piece of the data.
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diff --git a/src/zstream.c b/src/zstream.c
index 963c9a3..affa556 100644
--- a/src/zstream.c
+++ b/src/zstream.c
@@ -87,9 +87,52 @@ size_t git_zstream_suggest_output_len(git_zstream *zstream)
return ZSTREAM_BUFFER_MIN_EXTRA;
}
+int git_zstream_get_output_chunk(
+ void *out, size_t *out_len, git_zstream *zstream)
+{
+ size_t in_queued, in_used, out_queued;
+
+ /* set up input data */
+ zstream->z.next_in = (Bytef *)zstream->in;
+
+ /* feed as much data to zlib as it can consume, at most UINT_MAX */
+ if (zstream->in_len > UINT_MAX) {
+ zstream->z.avail_in = UINT_MAX;
+ zstream->flush = Z_NO_FLUSH;
+ } else {
+ zstream->z.avail_in = (uInt)zstream->in_len;
+ zstream->flush = Z_FINISH;
+ }
+ in_queued = (size_t)zstream->z.avail_in;
+
+ /* set up output data */
+ zstream->z.next_out = out;
+ zstream->z.avail_out = (uInt)*out_len;
+
+ if ((size_t)zstream->z.avail_out != *out_len)
+ zstream->z.avail_out = UINT_MAX;
+ out_queued = (size_t)zstream->z.avail_out;
+
+ /* compress next chunk */
+ if (zstream->type == GIT_ZSTREAM_INFLATE)
+ zstream->zerr = inflate(&zstream->z, zstream->flush);
+ else
+ zstream->zerr = deflate(&zstream->z, zstream->flush);
+
+ if (zstream_seterr(zstream))
+ return -1;
+
+ in_used = (in_queued - zstream->z.avail_in);
+ zstream->in_len -= in_used;
+ zstream->in += in_used;
+
+ *out_len = (out_queued - zstream->z.avail_out);
+
+ return 0;
+}
+
int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream)
{
- int zflush = Z_FINISH;
size_t out_remain = *out_len;
if (zstream->in_len && zstream->zerr == Z_STREAM_END) {
@@ -98,47 +141,17 @@ int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream)
}
while (out_remain > 0 && zstream->zerr != Z_STREAM_END) {
- size_t out_queued, in_queued, out_used, in_used;
+ size_t out_written = out_remain;
- /* set up in data */
- zstream->z.next_in = (Bytef *)zstream->in;
- zstream->z.avail_in = (uInt)zstream->in_len;
-
- if ((size_t)zstream->z.avail_in != zstream->in_len) {
- zstream->z.avail_in = UINT_MAX;
- zflush = Z_NO_FLUSH;
- } else {
- zflush = Z_FINISH;
- }
- in_queued = (size_t)zstream->z.avail_in;
-
- /* set up out data */
- zstream->z.next_out = out;
- zstream->z.avail_out = (uInt)out_remain;
- if ((size_t)zstream->z.avail_out != out_remain)
- zstream->z.avail_out = UINT_MAX;
- out_queued = (size_t)zstream->z.avail_out;
-
- /* compress next chunk */
- if (zstream->type == GIT_ZSTREAM_INFLATE)
- zstream->zerr = inflate(&zstream->z, zflush);
- else
- zstream->zerr = deflate(&zstream->z, zflush);
-
- if (zstream_seterr(zstream))
+ if (git_zstream_get_output_chunk(out, &out_written, zstream) < 0)
return -1;
- out_used = (out_queued - zstream->z.avail_out);
- out_remain -= out_used;
- out = ((char *)out) + out_used;
-
- in_used = (in_queued - zstream->z.avail_in);
- zstream->in_len -= in_used;
- zstream->in += in_used;
+ out_remain -= out_written;
+ out = ((char *)out) + out_written;
}
/* either we finished the input or we did not flush the data */
- assert(zstream->in_len > 0 || zflush == Z_FINISH);
+ assert(zstream->in_len > 0 || zstream->flush == Z_FINISH);
/* set out_size to number of bytes actually written to output */
*out_len = *out_len - out_remain;
diff --git a/src/zstream.h b/src/zstream.h
index fcc4a31..cfe2b39 100644
--- a/src/zstream.h
+++ b/src/zstream.h
@@ -23,6 +23,7 @@ typedef struct {
git_zstream_t type;
const char *in;
size_t in_len;
+ int flush;
int zerr;
} git_zstream;
@@ -35,6 +36,11 @@ int git_zstream_set_input(git_zstream *zstream, const void *in, size_t in_len);
size_t git_zstream_suggest_output_len(git_zstream *zstream);
+/* get as much output as is available in the input buffer */
+int git_zstream_get_output_chunk(
+ void *out, size_t *out_len, git_zstream *zstream);
+
+/* get all the output from the entire input buffer */
int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream);
bool git_zstream_done(git_zstream *zstream);