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-rw-r--r--ext/compressors/bzip2_compress/bzip2_compress.c3
-rw-r--r--ext/compressors/nop_compress/nop_compress.c2
-rw-r--r--ext/compressors/snappy_compress/snappy_compress.c56
3 files changed, 38 insertions, 23 deletions
diff --git a/ext/compressors/bzip2_compress/bzip2_compress.c b/ext/compressors/bzip2_compress/bzip2_compress.c
index a6c7afa05bc..01290963f25 100644
--- a/ext/compressors/bzip2_compress/bzip2_compress.c
+++ b/ext/compressors/bzip2_compress/bzip2_compress.c
@@ -14,7 +14,8 @@ bzip2_compress(
static int
bzip2_decompress(WT_COMPRESSOR *, WT_SESSION *, const WT_ITEM *, WT_ITEM *);
-static WT_COMPRESSOR bzip2_compressor = { bzip2_compress, bzip2_decompress };
+static WT_COMPRESSOR bzip2_compressor = {
+ bzip2_compress, bzip2_decompress, NULL };
#define __UNUSED(v) ((void)(v))
diff --git a/ext/compressors/nop_compress/nop_compress.c b/ext/compressors/nop_compress/nop_compress.c
index 32b329d6482..e3a729e0556 100644
--- a/ext/compressors/nop_compress/nop_compress.c
+++ b/ext/compressors/nop_compress/nop_compress.c
@@ -11,7 +11,7 @@ nop_compress(WT_COMPRESSOR *, WT_SESSION *, const WT_ITEM *, WT_ITEM *, int *);
static int
nop_decompress(WT_COMPRESSOR *, WT_SESSION *, const WT_ITEM *, WT_ITEM *);
-static WT_COMPRESSOR nop_compressor = { nop_compress, nop_decompress };
+static WT_COMPRESSOR nop_compressor = { nop_compress, nop_decompress, NULL };
#define __UNUSED(v) ((void)(v))
diff --git a/ext/compressors/snappy_compress/snappy_compress.c b/ext/compressors/snappy_compress/snappy_compress.c
index 7dea67f4ae7..3ad8b58e6cc 100644
--- a/ext/compressors/snappy_compress/snappy_compress.c
+++ b/ext/compressors/snappy_compress/snappy_compress.c
@@ -9,15 +9,15 @@
WT_EXTENSION_API *wt_api;
static int
-wt_snappy_compress(WT_COMPRESSOR *compressor, WT_SESSION *session,
- const WT_ITEM *source, WT_ITEM *dest, int *);
-
+wt_snappy_compress(
+ WT_COMPRESSOR *, WT_SESSION *, const WT_ITEM *, WT_ITEM *, int *);
static int
-wt_snappy_decompress(WT_COMPRESSOR *compressor, WT_SESSION *session,
- const WT_ITEM *source, WT_ITEM *dest);
-
+wt_snappy_decompress(WT_COMPRESSOR *, WT_SESSION *, const WT_ITEM *, WT_ITEM *);
+static int
+wt_snappy_pre_size(WT_COMPRESSOR *, WT_SESSION *, const WT_ITEM *, WT_ITEM *);
+
static WT_COMPRESSOR wt_snappy_compressor = {
- wt_snappy_compress, wt_snappy_decompress };
+ wt_snappy_compress, wt_snappy_decompress, wt_snappy_pre_size };
#define __UNUSED(v) ((void)(v))
@@ -76,16 +76,12 @@ wt_snappy_compress(WT_COMPRESSOR *compressor, WT_SESSION *session,
__UNUSED(compressor);
- /* Snappy requires that the dest buffer be somewhat larger
- * than the source, but WT hands us a a dest buffer the same
- * size. This leads to an unfortunate extra copy, but it
- * can't be helped with the current WT interface and snappy
- * API. We use a scratch buffer for temp storage, it should
- * be much faster than malloc.
+ /* dst->size was computed in wt_snappy_pre_size, so we know
+ * it's big enough. Skip past the space we'll use to store
+ * the compressed buf size.
*/
- snaplen = snappy_max_compressed_length(src->size);
- buf = wiredtiger_scr_alloc(session, snaplen);
- snapbuf = (char *)buf;
+ snaplen = dst->size - sizeof(size_t);
+ snapbuf = (char *)dst->data + sizeof(size_t);
/* snaplen is an input and an output arg. */
snret = snappy_compress((char *)src->data, src->size,
@@ -95,14 +91,12 @@ wt_snappy_compress(WT_COMPRESSOR *compressor, WT_SESSION *session,
/* On decompression, snappy requires the exact
* compressed buffer size (the current value of
* snaplen). WT does not preserve that, it rounds
- * the length up. So we save the snaplen at the
+ * the length up. So save snaplen at the
* beginning of the destination buffer.
*/
if (snaplen + sizeof(size_t) < dst->size) {
destp = (unsigned char *)dst->data;
*(size_t *)destp = snaplen;
- destp += sizeof(size_t);
- memcpy(destp, snapbuf, snaplen);
dst->size = (uint32_t)(snaplen + sizeof(size_t));
*compression_failed = 0;
}
@@ -115,8 +109,6 @@ wt_snappy_compress(WT_COMPRESSOR *compressor, WT_SESSION *session,
else
ret = wt_snappy_error(session, "snappy_compress", snret);
- wiredtiger_scr_free(session, buf);
-
return (ret);
}
@@ -152,4 +144,26 @@ wt_snappy_decompress(WT_COMPRESSOR *compressor, WT_SESSION *session,
return (ret);
}
+
+static int
+wt_snappy_pre_size(WT_COMPRESSOR *compressor, WT_SESSION *session,
+ const WT_ITEM *src, WT_ITEM *dst)
+{
+ size_t snaplen;
+
+ __UNUSED(compressor);
+ __UNUSED(session);
+
+ /* Snappy requires that the dest buffer be somewhat larger
+ * than the source. Fortunately, this is fast to compute, and
+ * will give us a dest buffer in wt_snappy_compress that we
+ * can compress to directly. We add space in the dest buffer
+ * to store the accurate compressed size.
+ */
+ snaplen = snappy_max_compressed_length(src->size);
+ dst->size = (uint32_t)(snaplen + sizeof(size_t));
+ return (0);
+}
+
+
/* End implementation of WT_COMPRESSOR. */