aboutsummaryrefslogtreecommitdiffstats
path: root/erts
diff options
context:
space:
mode:
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
parent9cdf92fc35006d34d7029ef0fc34c0daf9e1330b (diff)
downloadotp-69b8d1ab13473f851f8957e2bb6f5486f64612ad.tar.gz
otp-69b8d1ab13473f851f8957e2bb6f5486f64612ad.tar.bz2
otp-69b8d1ab13473f851f8957e2bb6f5486f64612ad.zip
zlib: support extraction of inflation dictionary
Diffstat (limited to 'erts')
-rw-r--r--erts/doc/src/zlib.xml11
-rw-r--r--erts/emulator/drivers/common/zlib_drv.c51
-rw-r--r--erts/preloaded/src/zlib.erl41
3 files changed, 72 insertions, 31 deletions
diff --git a/erts/doc/src/zlib.xml b/erts/doc/src/zlib.xml
index 138414a880..1a7c2d2b6f 100644
--- a/erts/doc/src/zlib.xml
+++ b/erts/doc/src/zlib.xml
@@ -576,6 +576,17 @@ unpack(Z, Compressed, Dict) ->
</func>
<func>
+ <name name="inflateGetDictionary" arity="1"/>
+ <fsummary>Return the decompression dictionary.</fsummary>
+ <desc>
+ <p>Returns the decompression dictionary currently in use
+ by the stream. This function must be called between
+ <seealso marker="#inflateInit/1"><c>inflateInit/1,2</c></seealso>
+ and <seealso marker="#inflateEnd/1"><c>inflateEnd</c></seealso>.</p>
+ </desc>
+ </func>
+
+ <func>
<name name="open" arity="0"/>
<fsummary>Open a stream and return a stream reference.</fsummary>
<desc>
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;
diff --git a/erts/preloaded/src/zlib.erl b/erts/preloaded/src/zlib.erl
index fa0f28c5c3..8cd3e39fd7 100644
--- a/erts/preloaded/src/zlib.erl
+++ b/erts/preloaded/src/zlib.erl
@@ -23,7 +23,8 @@
-export([open/0,close/1,deflateInit/1,deflateInit/2,deflateInit/6,
deflateSetDictionary/2,deflateReset/1,deflateParams/3,
deflate/2,deflate/3,deflateEnd/1,
- inflateInit/1,inflateInit/2,inflateSetDictionary/2,
+ inflateInit/1,inflateInit/2,
+ inflateSetDictionary/2,inflateGetDictionary/1,
inflateSync/1,inflateReset/1,inflate/2,inflateEnd/1,
inflateChunk/1, inflateChunk/2,
setBufSize/2,getBufSize/1,
@@ -98,25 +99,26 @@
-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_CHUNK, 25).
+-define(INFLATE_GETDICT, 11).
+-define(INFLATE_SYNC, 12).
+-define(INFLATE_RESET, 13).
+-define(INFLATE_END, 14).
+-define(INFLATE, 15).
+-define(INFLATE_CHUNK, 26).
--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).
%%------------------------------------------------------------------------
@@ -242,6 +244,13 @@ inflateInit(Z, WindowBits) ->
inflateSetDictionary(Z, Dictionary) ->
call(Z, ?INFLATE_SETDICT, Dictionary).
+-spec inflateGetDictionary(Z) -> Dictionary when
+ Z :: zstream(),
+ Dictionary :: iolist().
+inflateGetDictionary(Z) ->
+ _ = call(Z, ?INFLATE_GETDICT, []),
+ collect(Z).
+
-spec inflateSync(zstream()) -> 'ok'.
inflateSync(Z) ->
call(Z, ?INFLATE_SYNC, []).