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authorGuilherme Andrade <[email protected]>2016-07-23 19:10:10 +0100
committerGuilherme Andrade <[email protected]>2016-07-23 19:16:22 +0100
commit69b8d1ab13473f851f8957e2bb6f5486f64612ad (patch)
treeaefd3a0dcc2828d302c7af194bc169768aaab8f6 /erts/emulator/drivers/common/zlib_drv.c
parent9cdf92fc35006d34d7029ef0fc34c0daf9e1330b (diff)
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zlib: support extraction of inflation dictionary
Diffstat (limited to 'erts/emulator/drivers/common/zlib_drv.c')
-rw-r--r--erts/emulator/drivers/common/zlib_drv.c51
1 files changed, 36 insertions, 15 deletions
diff --git a/erts/emulator/drivers/common/zlib_drv.c b/erts/emulator/drivers/common/zlib_drv.c
index 440ba956d8..acbe675c41 100644
--- a/erts/emulator/drivers/common/zlib_drv.c
+++ b/erts/emulator/drivers/common/zlib_drv.c
@@ -44,30 +44,34 @@
#define INFLATE_INIT 8
#define INFLATE_INIT2 9
#define INFLATE_SETDICT 10
-#define INFLATE_SYNC 11
-#define INFLATE_RESET 12
-#define INFLATE_END 13
-#define INFLATE 14
+#define INFLATE_GETDICT 11
+#define INFLATE_SYNC 12
+#define INFLATE_RESET 13
+#define INFLATE_END 14
+#define INFLATE 15
-#define CRC32_0 15
-#define CRC32_1 16
-#define CRC32_2 17
+#define CRC32_0 16
+#define CRC32_1 17
+#define CRC32_2 18
-#define SET_BUFSZ 18
-#define GET_BUFSZ 19
-#define GET_QSIZE 20
+#define SET_BUFSZ 19
+#define GET_BUFSZ 20
+#define GET_QSIZE 21
-#define ADLER32_1 21
-#define ADLER32_2 22
+#define ADLER32_1 22
+#define ADLER32_2 23
-#define CRC32_COMBINE 23
-#define ADLER32_COMBINE 24
+#define CRC32_COMBINE 24
+#define ADLER32_COMBINE 25
-#define INFLATE_CHUNK 25
+#define INFLATE_CHUNK 26
#define DEFAULT_BUFSZ 4000
+/* According to zlib documentation, it can never exceed this */
+#define INFL_DICT_SZ 32768
+
/* This flag is used in the same places, where zlib return codes
* (Z_OK, Z_STREAM_END, Z_NEED_DICT) are. So, we need to set it to
* relatively large value to avoid possible value clashes in future.
@@ -248,6 +252,18 @@ static int zlib_output(ZLibData* d)
return zlib_output_init(d);
}
+static int zlib_inflate_get_dictionary(ZLibData* d)
+{
+ ErlDrvBinary* dbin = driver_alloc_binary(INFL_DICT_SZ);
+ uInt dlen = 0;
+ int res = inflateGetDictionary(&d->s, (unsigned char*)dbin->orig_bytes, &dlen);
+ if ((res == Z_OK) && (driver_output_binary(d->port, NULL, 0, dbin, 0, dlen) < 0)) {
+ res = Z_ERRNO;
+ }
+ driver_free_binary(dbin);
+ return res;
+}
+
static int zlib_inflate(ZLibData* d, int flush)
{
int res = Z_OK;
@@ -586,6 +602,11 @@ static ErlDrvSSizeT zlib_ctl(ErlDrvData drv_data, unsigned int command, char *bu
res = inflateSetDictionary(&d->s, (unsigned char*)buf, len);
return zlib_return(res, rbuf, rlen);
+ case INFLATE_GETDICT:
+ if (d->state != ST_INFLATE) goto badarg;
+ res = zlib_inflate_get_dictionary(d);
+ return zlib_return(res, rbuf, rlen);
+
case INFLATE_SYNC:
if (d->state != ST_INFLATE) goto badarg;
if (len != 0) goto badarg;