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-rw-r--r--erts/doc/src/zlib.xml47
-rw-r--r--erts/emulator/drivers/common/zlib_drv.c73
-rw-r--r--erts/preloaded/ebin/zlib.beambin13176 -> 14160 bytes
-rw-r--r--erts/preloaded/src/zlib.erl39
4 files changed, 158 insertions, 1 deletions
diff --git a/erts/doc/src/zlib.xml b/erts/doc/src/zlib.xml
index da8ccdecdf..673b743e2e 100644
--- a/erts/doc/src/zlib.xml
+++ b/erts/doc/src/zlib.xml
@@ -312,6 +312,53 @@ list_to_binary([B1,B2])</pre>
</desc>
</func>
<func>
+ <name name="inflateChunk" arity="2"/>
+ <fsummary>Decompress data with limited output size</fsummary>
+ <desc>
+ <p>Like <c>inflate/2</c>, but decompress no more data than
+ will fit in the buffer configured via <c>setBufSize/2</c>.
+ Is is useful when decompressing a stream with a high compression
+ ratio such that a small amount of compressed input may expand up to
+ 1000 times.
+ It returns <c>{more, Decompressed}</c>, when there is more output
+ available, and <c>inflateChunk/1</c> should be used to read it.
+ It may introduce some output latency (reading
+ input without producing any output).</p>
+ <p>If a preset dictionary is needed at this point (see
+ <c>inflateSetDictionary</c> below), <c>inflateChunk/2</c> throws a
+ <c>{need_dictionary,Adler}</c> exception where <c>Adler</c> is
+ the adler32 checksum of the dictionary chosen by the
+ compressor.</p>
+
+ <pre>
+walk(Compressed, Handler) ->
+ Z = zlib:open(),
+ zlib:inflateInit(Z),
+ % Limit single uncompressed chunk size to 512kb
+ zlib:setBufSize(Z, 512 * 1024),
+ loop(Z, Handler, zlib:inflateChunk(Z, Compressed)),
+ zlib:inflateEnd(Z),
+ zlib:close(Z).
+
+loop(Z, Handler, {more, Uncompressed}) ->
+ Handler(Uncompressed),
+ loop(Z, Handler, zlib:inflateChunk(Z));
+loop(Z, Handler, Uncompressed) ->
+ Handler(Uncompressed).
+ </pre>
+ </desc>
+ </func>
+ <func>
+ <name name="inflateChunk" arity="1"/>
+ <fsummary>Read next uncompressed chunk</fsummary>
+ <desc>
+ <p>Read next chunk of uncompressed data, initialized by
+ <c>inflateChunk/2</c>.</p>
+ <p>This function should be repeatedly called, while it returns
+ <c>{more, Decompressed}</c>.</p>
+ </desc>
+ </func>
+ <func>
<name name="inflateSetDictionary" arity="2"/>
<fsummary>Initialize the decompression dictionary</fsummary>
<desc>
diff --git a/erts/emulator/drivers/common/zlib_drv.c b/erts/emulator/drivers/common/zlib_drv.c
index 3143e4511d..f7b2d91d23 100644
--- a/erts/emulator/drivers/common/zlib_drv.c
+++ b/erts/emulator/drivers/common/zlib_drv.c
@@ -62,8 +62,17 @@
#define CRC32_COMBINE 23
#define ADLER32_COMBINE 24
+#define INFLATE_CHUNK 25
+
+
#define DEFAULT_BUFSZ 4000
+/* 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.
+ * */
+#define INFLATE_HAS_MORE 100
+
static int zlib_init(void);
static ErlDrvData zlib_start(ErlDrvPort port, char* buf);
static void zlib_stop(ErlDrvData e);
@@ -295,6 +304,58 @@ static int zlib_inflate(ZLibData* d, int flush)
return res;
}
+static int zlib_inflate_chunk(ZLibData* d)
+{
+ int res = Z_OK;
+
+ if ((d->bin == NULL) && (zlib_output_init(d) < 0)) {
+ errno = ENOMEM;
+ return Z_ERRNO;
+ }
+
+ while ((driver_sizeq(d->port) > 0) && (d->s.avail_out > 0) &&
+ (res != Z_STREAM_END)) {
+ int vlen;
+ SysIOVec* iov = driver_peekq(d->port, &vlen);
+ int len;
+
+ d->s.next_in = iov[0].iov_base;
+ d->s.avail_in = iov[0].iov_len;
+ while((d->s.avail_in > 0) && (d->s.avail_out > 0) && (res != Z_STREAM_END)) {
+ res = inflate(&d->s, Z_NO_FLUSH);
+ if (res == Z_NEED_DICT) {
+ /* Essential to eat the header bytes that zlib has looked at */
+ len = iov[0].iov_len - d->s.avail_in;
+ driver_deq(d->port, len);
+ return res;
+ }
+ if (res == Z_BUF_ERROR) {
+ /* Was possible more output, but actually not */
+ res = Z_OK;
+ }
+ else if (res < 0) {
+ return res;
+ }
+ }
+ len = iov[0].iov_len - d->s.avail_in;
+ driver_deq(d->port, len);
+ }
+
+ /* We are here because all input was consumed or EOS reached or output
+ * buffer is full */
+ if (d->want_crc) {
+ d->crc = crc32(d->crc, (unsigned char*) d->bin->orig_bytes,
+ d->binsz - d->s.avail_out);
+ }
+ zlib_output(d);
+ if ((res == Z_OK) && (d->s.avail_in > 0))
+ res = INFLATE_HAS_MORE;
+ else if (res == Z_STREAM_END) {
+ d->inflate_eos_seen = 1;
+ }
+ return res;
+}
+
static int zlib_deflate(ZLibData* d, int flush)
{
int res = Z_OK;
@@ -568,6 +629,18 @@ static ErlDrvSSizeT zlib_ctl(ErlDrvData drv_data, unsigned int command, char *bu
return zlib_return(res, rbuf, rlen);
}
+ case INFLATE_CHUNK:
+ if (d->state != ST_INFLATE) goto badarg;
+ if (len != 0) goto badarg;
+ res = zlib_inflate_chunk(d);
+ if (res == INFLATE_HAS_MORE) {
+ return zlib_value2(4, 0, rbuf, rlen);
+ } else if (res == Z_NEED_DICT) {
+ return zlib_value2(3, d->s.adler, rbuf, rlen);
+ } else {
+ return zlib_return(res, rbuf, rlen);
+ }
+
case GET_QSIZE:
return zlib_value(driver_sizeq(d->port), rbuf, rlen);
diff --git a/erts/preloaded/ebin/zlib.beam b/erts/preloaded/ebin/zlib.beam
index 193cebdc31..8783f189a4 100644
--- a/erts/preloaded/ebin/zlib.beam
+++ b/erts/preloaded/ebin/zlib.beam
Binary files differ
diff --git a/erts/preloaded/src/zlib.erl b/erts/preloaded/src/zlib.erl
index df7b2e6198..5ebc67dcaa 100644
--- a/erts/preloaded/src/zlib.erl
+++ b/erts/preloaded/src/zlib.erl
@@ -24,6 +24,7 @@
deflate/2,deflate/3,deflateEnd/1,
inflateInit/1,inflateInit/2,inflateSetDictionary/2,
inflateSync/1,inflateReset/1,inflate/2,inflateEnd/1,
+ inflateChunk/1, inflateChunk/2,
setBufSize/2,getBufSize/1,
crc32/1,crc32/2,crc32/3,adler32/2,adler32/3,getQSize/1,
crc32_combine/4,adler32_combine/4,
@@ -100,6 +101,7 @@
-define(INFLATE_RESET, 12).
-define(INFLATE_END, 13).
-define(INFLATE, 14).
+-define(INFLATE_CHUNK, 25).
-define(CRC32_0, 15).
-define(CRC32_1, 16).
@@ -263,6 +265,39 @@ inflate(Z, Data) ->
erlang:error(badarg)
end.
+-spec inflateChunk(Z, Data) -> Decompressed | {more, Decompressed} when
+ Z :: zstream(),
+ Data :: iodata(),
+ Decompressed :: iolist().
+inflateChunk(Z, Data) ->
+ try port_command(Z, Data) of
+ true ->
+ inflateChunk(Z)
+ catch
+ error:_Err ->
+ flush(Z),
+ erlang:error(badarg)
+ end.
+
+-spec inflateChunk(Z) -> Decompressed | {more, Decompressed} when
+ Z :: zstream(),
+ Decompressed :: iolist().
+inflateChunk(Z) ->
+ Status = call(Z, ?INFLATE_CHUNK, []),
+ Data = receive
+ {Z, {data, Bin}} ->
+ Bin
+ after 0 ->
+ []
+ end,
+
+ case Status of
+ Good when (Good == ok) orelse (Good == stream_end) ->
+ Data;
+ inflate_has_more ->
+ {more, Data}
+ end.
+
-spec inflateEnd(Z) -> 'ok' when
Z :: zstream().
inflateEnd(Z) ->
@@ -514,7 +549,9 @@ call(Z, Cmd, Arg) ->
[2,A,B,C,D] ->
(A bsl 24)+(B bsl 16)+(C bsl 8)+D;
[3,A,B,C,D] ->
- erlang:error({need_dictionary,(A bsl 24)+(B bsl 16)+(C bsl 8)+D})
+ erlang:error({need_dictionary,(A bsl 24)+(B bsl 16)+(C bsl 8)+D});
+ [4, _, _, _, _] ->
+ inflate_has_more
catch
error:badarg -> %% Rethrow loses port_control from stacktrace.
erlang:error(badarg)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 17:14:09 +0000