Merge branch 'g-andrade/kernel/fetch_ztream_dictionary/PR-1139/OTP-13842'

* g-andrade/kernel/fetch_ztream_dictionary/PR-1139/OTP-13842:
  Update preloaded modules
  Specify min zlib ver on inflateGetDictionary doc
  Skip inflateGetDictionary test case if unsupported
  zlib: Only link inflateGetDictionary if available
  zlib: Add test case for inflateGetDictionary
  zlib: support extraction of inflation dictionary

6 files changed, 124 insertions, 32 deletions

diff --git a/erts/configure.in b/erts/configure.in
index b1830979aa..9f3d267791 100644
--- a/erts/configure.in
+++ b/erts/configure.in
@@ -1359,6 +1359,8 @@ AC_ARG_ENABLE(builtin-zlib,
 Z_LIB=
 
 if test "x$enable_builtin_zlib" = "xyes"; then
+  AC_DEFINE(HAVE_ZLIB_INFLATEGETDICTIONARY, 1,
+            [Define if your zlib version defines inflateGetDictionary.])
   AC_MSG_NOTICE([Using our own built-in zlib source])
 else
 AC_MSG_CHECKING(for zlib 1.2.5 or higher)
@@ -1385,6 +1387,11 @@ error
  AC_MSG_RESULT(no)
 ])
 LIBS=$zlib_save_LIBS
+
+AC_MSG_CHECKING(for zlib inflateGetDictionary presence)
+AC_SEARCH_LIBS(inflateGetDictionary, [z],
+               AC_DEFINE(HAVE_ZLIB_INFLATEGETDICTIONARY, 1,
+                         [Define if your zlib version defines inflateGetDictionary.]))
 fi
 AC_SUBST(Z_LIB)
 
diff --git a/erts/doc/src/zlib.xml b/erts/doc/src/zlib.xml
index 138414a880..e1924fffee 100644
--- a/erts/doc/src/zlib.xml
+++ b/erts/doc/src/zlib.xml
@@ -576,6 +576,18 @@ 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>
+        <p>Only supported if ERTS was compiled with zlib >= 1.2.8.</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..066cf87c9d 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 +252,20 @@ static int zlib_output(ZLibData* d)
     return zlib_output_init(d);
 }
 
+#ifdef HAVE_ZLIB_INFLATEGETDICTIONARY
+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;
+}
+#endif
+
 static int zlib_inflate(ZLibData* d, int flush)
 {
     int res = Z_OK;
@@ -586,6 +604,16 @@ 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:
+#ifdef HAVE_ZLIB_INFLATEGETDICTIONARY
+        if (d->state != ST_INFLATE) goto badarg;
+        res = zlib_inflate_get_dictionary(d);
+        return zlib_return(res, rbuf, rlen);
+#else
+        errno = ENOTSUP;
+        return zlib_return(Z_ERRNO, rbuf, rlen);
+#endif
+
     case INFLATE_SYNC:
 	if (d->state != ST_INFLATE) goto badarg;
 	if (len != 0) goto badarg;
diff --git a/erts/preloaded/ebin/zlib.beam b/erts/preloaded/ebin/zlib.beam
index 4c48742344..6a7ad9164f 100644
--- a/erts/preloaded/ebin/zlib.beam
+++ b/erts/preloaded/ebin/zlib.beam
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, []).
diff --git a/lib/kernel/test/zlib_SUITE.erl b/lib/kernel/test/zlib_SUITE.erl
index f8257bd20c..4b67fce9a8 100644
--- a/lib/kernel/test/zlib_SUITE.erl
+++ b/lib/kernel/test/zlib_SUITE.erl
@@ -83,7 +83,7 @@ groups() ->
       [api_open_close, api_deflateInit,
        api_deflateSetDictionary, api_deflateReset,
        api_deflateParams, api_deflate, api_deflateEnd,
-       api_inflateInit, api_inflateSetDictionary,
+       api_inflateInit, api_inflateSetDictionary, api_inflateGetDictionary,
        api_inflateSync, api_inflateReset, api_inflate, api_inflateChunk,
        api_inflateEnd, api_setBufsz, api_getBufsz, api_crc32,
        api_adler32, api_getQSize, api_un_compress, api_un_zip,
@@ -288,6 +288,42 @@ api_inflateSetDictionary(Config) when is_list(Config) ->
     ?m({'EXIT',{stream_error,_}}, zlib:inflateSetDictionary(Z1,Dict)),
     ?m(ok, zlib:close(Z1)).
 
+%% Test inflateGetDictionary.
+api_inflateGetDictionary(Config) when is_list(Config) ->
+    Z1 = zlib:open(),
+    IsOperationSupported =
+        case catch zlib:inflateGetDictionary(Z1) of
+            {'EXIT',{einval,_}} -> true;
+            {'EXIT',{enotsup,_}} -> false
+        end,
+    _ = zlib:close(Z1),
+    api_inflateGetDictionary_if_supported(IsOperationSupported).
+
+api_inflateGetDictionary_if_supported(false) ->
+    {skip, "inflateGetDictionary/1 unsupported in current setup"};
+api_inflateGetDictionary_if_supported(true) ->
+    % Compress payload using custom dictionary
+    Z1 = zlib:open(),
+    ?m(ok, zlib:deflateInit(Z1)),
+    Dict = <<"foobar barfoo foo bar far boo">>,
+    ?m(_, zlib:deflateSetDictionary(Z1, Dict)),
+    Payload = <<"foobarbarbar">>,
+    Compressed = zlib:deflate(Z1, Payload, finish),
+    ?m(ok, zlib:close(Z1)),
+
+    % Decompress and test dictionary extraction
+    Z2 = zlib:open(),
+    ?m(ok, zlib:inflateInit(Z2)),
+    ?m(<<>>, iolist_to_binary(zlib:inflateGetDictionary(Z2))),
+    ?m({'EXIT',{stream_error,_}}, zlib:inflateSetDictionary(Z2, Dict)),
+    ?m({'EXIT',{{need_dictionary,_},_}}, zlib:inflate(Z2, Compressed)),
+    ?m(ok, zlib:inflateSetDictionary(Z2, Dict)),
+    ?m(Dict, iolist_to_binary(zlib:inflateGetDictionary(Z2))),
+    ?m(Payload, iolist_to_binary(zlib:inflate(Z2, Compressed))),
+    ?m(ok, zlib:close(Z2)),
+    ?m(?BARG, zlib:inflateSetDictionary(Z2, Dict)),
+    ok.
+
 %% Test inflateSync.
 api_inflateSync(Config) when is_list(Config) ->
     {skip,"inflateSync/1 sucks"}.