diff options
Diffstat (limited to 'erts/doc')
| -rw-r--r-- | erts/doc/src/erl_nif.xml | 284 | ||||
| -rw-r--r-- | erts/doc/src/erlang.xml | 17 | ||||
| -rw-r--r-- | erts/doc/src/notes.xml | 2 | ||||
| -rw-r--r-- | erts/doc/src/zlib.xml | 227 |
4 files changed, 474 insertions, 56 deletions
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 5a69bed34c..419e41693e 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -206,7 +206,7 @@ ok <seealso marker="#enif_make_resource"> <c>enif_make_resource</c></seealso>. The term returned by <c>enif_make_resource</c> is opaque in nature. - It can be stored and passed between processes on the same node, but + It can be stored and passed between processes, but the only real end usage is to pass it back as an argument to a NIF. The NIF can then call <seealso marker="#enif_get_resource"> <c>enif_get_resource</c></seealso> and get back a pointer to the @@ -344,6 +344,81 @@ return term;</code> <c>enif_convert_time_unit()</c></seealso></item> </list> </item> + <tag><marker id="enif_ioq"/>I/O Queues</tag> + <item> + <p>The Erlang nif library contains function for easily working + with I/O vectors as used by the unix system call <c>writev</c>. + The I/O Queue is not thread safe, so some other synchronization + mechanism has to be used.</p> + <list type="bulleted"> + <item><seealso marker="#SysIOVec"> + <c>SysIOVec</c></seealso></item> + <item><seealso marker="#ErlNifIOVec"> + <c>ErlNifIOVec</c></seealso></item> + <item><seealso marker="#enif_ioq_create"> + <c>enif_ioq_create()</c></seealso></item> + <item><seealso marker="#enif_ioq_destroy"> + <c>enif_ioq_destroy()</c></seealso></item> + <item><seealso marker="#enif_ioq_enq_binary"> + <c>enif_ioq_enq_binary()</c></seealso></item> + <item><seealso marker="#enif_ioq_enqv"> + <c>enif_ioq_enqv()</c></seealso></item> + <item><seealso marker="#enif_ioq_deq"> + <c>enif_ioq_deq()</c></seealso></item> + <item><seealso marker="#enif_ioq_peek"> + <c>enif_ioq_peek()</c></seealso></item> + <item><seealso marker="#enif_inspect_iovec"> + <c>enif_inspect_iovec()</c></seealso></item> + <item><seealso marker="#enif_free_iovec"> + <c>enif_free_iovec()</c></seealso></item> + </list> + <p>Typical usage when writing to a file descriptor looks like this:</p> + <code type="none"><![CDATA[ +int writeiovec(ErlNifEnv *env, ERL_NIF_TERM term, ERL_NIF_TERM *tail, + ErlNifIOQueue *q, int fd) { + + ErlNifIOVec vec, *iovec = &vec; + SysIOVec *sysiovec; + int saved_errno; + int iovcnt, n; + + if (!enif_inspect_iovec(env, 64, term, tail, &iovec)) + return -2; + + if (enif_ioq_size(q) > 0) { + /* If the I/O queue contains data we enqueue the iovec and + then peek the data to write out of the queue. */ + if (!enif_ioq_enqv(q, iovec, 0)) + return -3; + + sysiovec = enif_ioq_peek(q, &iovcnt); + } else { + /* If the I/O queue is empty we skip the trip through it. */ + iovcnt = iovec->iovcnt; + sysiovec = iovec->iov; + } + + /* Attempt to write the data */ + n = writev(fd, sysiovec, iovcnt); + saved_errno = errno; + + if (enif_ioq_size(q) == 0) { + /* If the I/O queue was initially empty we enqueue any + remaining data into the queue for writing later. */ + if (n >= 0 && !enif_ioq_enqv(q, iovec, n)) + return -3; + } else { + /* Dequeue any data that was written from the queue. */ + if (n > 0 && !enif_ioq_deq(q, n, NULL)) + return -4; + } + + /* return n, which is either number of bytes written or -1 if + some error happened */ + errno = saved_errno; + return n; +}]]></code> + </item> <tag><marker id="lengthy_work"/>Long-running NIFs</tag> <item> <p>As mentioned in the <seealso marker="#WARNING">warning</seealso> text @@ -837,6 +912,36 @@ typedef enum { </item> </taglist> </item> + <tag><marker id="SysIOVec"/><c>SysIOVec</c></tag> + <item> + <p>A system I/O vector, as used by <c>writev</c> on + Unix and <c>WSASend</c> on Win32. It is used in + <c>ErlNifIOVec</c> and by + <seealso marker="#enif_ioq_peek"><c>enif_ioq_peek</c></seealso>.</p> + </item> + <tag><marker id="ErlNifIOVec"/><c>ErlNifIOVec</c></tag> + <item> + <code type="none"> +typedef struct { + int iovcnt; + size_t size; + SysIOVec* iov; +} ErlNifIOVec;</code> + <p>An I/O vector containing <c>iovcnt</c> <c>SysIOVec</c>s + pointing to the data. It is used by + <seealso marker="#enif_inspect_iovec"> + <c>enif_inspect_iovec</c></seealso> and + <seealso marker="#enif_ioq_enqv"> + <c>enif_ioq_enqv</c></seealso>.</p> + </item> + <tag><marker id="ErlNifIOQueueOpts"/><c>ErlNifIOQueueOpts</c></tag> + <item> + Options to configure a <c>ErlNifIOQueue</c>. + <taglist> + <tag>ERL_NIF_IOQ_NORMAL</tag> + <item><p>Create a normal I/O Queue</p></item> + </taglist> + </item> </taglist> </section> @@ -1143,6 +1248,31 @@ typedef enum { </func> <func> + <name><ret>void</ret> + <nametext>enif_free_iovec(ErlNifIOvec* iov)</nametext></name> + <fsummary>Free an ErlIOVec</fsummary> + <desc> + <p>Frees an io vector returned from + <seealso marker="#enif_inspect_iovec"> + <c>enif_inspect_iovec</c></seealso>. + This is needed only if a <c>NULL</c> environment is passed to + <seealso marker="#enif_inspect_iovec"> + <c>enif_inspect_iovec</c></seealso>.</p> + <code type="none"><![CDATA[ +ErlNifIOVec *iovec = NULL; +size_t max_elements = 128; +ERL_NIF_TERM tail; +if (!enif_inspect_iovec(NULL, max_elements, term, &tail, iovec)) + return 0; + +// Do things with the iovec + +/* Free the iovector, possibly in another thread or nif function call */ +enif_free_iovec(iovec);]]></code> + </desc> + </func> + + <func> <name><ret>int</ret><nametext>enif_get_atom(ErlNifEnv* env, ERL_NIF_TERM term, char* buf, unsigned size, ErlNifCharEncoding encode)</nametext> </name> @@ -1449,6 +1579,127 @@ typedef enum { </func> <func> + <name><ret>int</ret><nametext>enif_inspect_iovec(ErlNifEnv* + env, size_t max_elements, ERL_NIF_TERM iovec_term, ERL_NIF_TERM* tail, + ErlNifIOVec** iovec)</nametext></name> + <fsummary>Inspect a list of binaries as an ErlNifIOVec.</fsummary> + <desc> + <p>Fills <c>iovec</c> with the list of binaries provided in + <c>iovec_term</c>. The number of elements handled in the call is + limited to <c>max_elements</c>, and <c>tail</c> is set to the + remainder of the list. Note that the output may be longer than + <c>max_elements</c> on some platforms. + </p> + <p>To create a list of binaries from an arbitrary iolist, use + <seealso marker="erts:erlang#iolist_to_iovec/1"> + <c>erlang:iolist_to_iovec/1</c></seealso>.</p> + <p>When calling this function, <c>iovec</c> should contain a pointer to + <c>NULL</c> or a ErlNifIOVec structure that should be used if + possible. e.g. + </p> + <code type="none"> +/* Don't use a pre-allocated structure */ +ErlNifIOVec *iovec = NULL; +enif_inspect_iovec(env, max_elements, term, &tail, &iovec); + +/* Use a stack-allocated vector as an optimization for vectors with few elements */ +ErlNifIOVec vec, *iovec = &vec; +enif_inspect_iovec(env, max_elements, term, &tail, &iovec); +</code> + <p>The contents of the <c>iovec</c> is valid until the called nif + function returns. If the <c>iovec</c> should be valid after the nif + call returns, it is possible to call this function with a + <c>NULL</c> environment. If no environment is given the <c>iovec</c> + owns the data in the vector and it has to be explicitly freed using + <seealso marker="#enif_free_iovec"><c>enif_free_iovec</c> + </seealso>.</p> + <p>Returns <c>true</c> on success, or <c>false</c> if <c>iovec_term</c> + not an iovec.</p> + </desc> + </func> + + <func> + <name><ret>ErlNifIOQueue *</ret> + <nametext>enif_ioq_create(ErlNifIOQueueOpts opts)</nametext></name> + <fsummary>Create a new IO Queue</fsummary> + <desc> + <p>Create a new I/O Queue that can be used to store data. + <c>opts</c> has to be set to <c>ERL_NIF_IOQ_NORMAL</c>. + </p> + </desc> + </func> + + <func> + <name><ret>void</ret> + <nametext>enif_ioq_destroy(ErlNifIOQueue *q)</nametext></name> + <fsummary>Destroy an IO Queue and free it's content</fsummary> + <desc> + <p>Destroy the I/O queue and free all of it's contents</p> + </desc> + </func> + + <func> + <name><ret>int</ret> + <nametext>enif_ioq_deq(ErlNifIOQueue *q, size_t count, size_t *size)</nametext></name> + <fsummary>Dequeue count bytes from the IO Queue</fsummary> + <desc> + <p>Dequeue <c>count</c> bytes from the I/O queue. + If <c>size</c> is not <c>NULL</c>, the new size of the queue + is placed there.</p> + <p>Returns <c>true</c> on success, or <c>false</c> if the I/O does + not contain <c>count</c> bytes. On failure the queue is left un-altered.</p> + </desc> + </func> + + <func> + <name><ret>int</ret> + <nametext>enif_ioq_enq_binary(ErlNifIOQueue *q, ErlNifBinary *bin, size_t skip)</nametext></name> + <fsummary>Enqueue the binary into the IO Queue</fsummary> + <desc> + <p>Enqueue the <c>bin</c> into <c>q</c> skipping the first <c>skip</c> bytes.</p> + <p>Returns <c>true</c> on success, or <c>false</c> if <c>skip</c> is greater + than the size of <c>bin</c>. Any ownership of the binary data is transferred + to the queue and <c>bin</c> is to be considered read-only for the rest of the NIF + call and then as released.</p> + </desc> + </func> + + <func> + <name><ret>int</ret> + <nametext>enif_ioq_enqv(ErlNifIOQueue *q, ErlNifIOVec *iovec, size_t skip)</nametext></name> + <fsummary>Enqueue the iovec into the IO Queue</fsummary> + <desc> + <p>Enqueue the <c>iovec</c> into <c>q</c> skipping the first <c>skip</c> bytes.</p> + <p>Returns <c>true</c> on success, or <c>false</c> if <c>skip</c> is greater + than the size of <c>iovec</c>.</p> + </desc> + </func> + + <func> + <name><ret>SysIOVec *</ret> + <nametext>enif_ioq_peek(ErlNifIOQueue *q, int *iovlen)</nametext></name> + <fsummary>Peek inside the IO Queue</fsummary> + <desc> + <p>Get the I/O queue as a pointer to an array of <c>SysIOVec</c>s. + It also returns the number of elements in <c>iovlen</c>. + This is the only way to get data out of the queue.</p> + <p>Nothing is removed from the queue by this function, that must be done + with <seealso marker="#enif_ioq_deq"><c>enif_ioq_deq</c></seealso>.</p> + <p>The returned array is suitable to use with the Unix system + call <c>writev</c>.</p> + </desc> + </func> + + <func> + <name><ret>size_t</ret> + <nametext>enif_ioq_size(ErlNifIOQueue *q)</nametext></name> + <fsummary>Get the current size of the IO Queue</fsummary> + <desc> + <p>Get the size of <c>q</c>.</p> + </desc> + </func> + + <func> <name><ret>int</ret> <nametext>enif_is_atom(ErlNifEnv* env, ERL_NIF_TERM term)</nametext> </name> @@ -1952,10 +2203,33 @@ typedef enum { details, see the <seealso marker="#enif_resource_example">example of creating and returning a resource object</seealso> in the User's Guide.</p> - <p>Notice that the only defined behavior of using a resource term in - an Erlang program is to store it and send it between processes on the - same node. Other operations, such as matching or - <c>term_to_binary</c>, have unpredictable (but harmless) results.</p> + <note> + <p>Since ERTS 9.0 (OTP-20.0), resource terms have a defined behavior + when compared and serialized through <c>term_to_binary</c> or passed + between nodes.</p> + <list type="bulleted"> + <item> + <p>Two resource terms will compare equal iff they + would yield the same resource object pointer when passed to + <seealso marker="#enif_get_resource"><c>enif_get_resource</c></seealso>.</p> + </item> + <item> + <p>A resoure term can be serialized with <c>term_to_binary</c> and later + be fully recreated if the resource object is still alive when + <c>binary_to_term</c> is called. A <em>stale</em> resource term will be + returned from <c>binary_to_term</c> if the resource object has + been deallocated. <seealso marker="#enif_get_resource"><c>enif_get_resource</c></seealso> + will return false for stale resource terms.</p> + <p>The same principles of serialization apply when passing + resource terms in messages to remote nodes and back again. A + resource term will act stale on all nodes except the node where + its resource object is still alive in memory.</p> + </item> + </list> + <p>Before ERTS 9.0 (OTP-20.0), all resource terms did + compare equal to each other and to empty binaries (<c><<>></c>). + If serialized, they would be recreated as plain empty binaries.</p> + </note> </desc> </func> diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 797b36bf13..e6b983b6c2 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -60,6 +60,14 @@ </desc> </datatype> <datatype> + <name>iovec()</name> + <desc> + <p>A list of binaries. This datatype is useful to use + together with <seealso marker="erl_nif#enif_inspect_iovec"> + <c>enif_inspect_iovec</c></seealso>.</p> + </desc> + </datatype> + <datatype> <name name="message_queue_data"></name> <desc> <p>See <seealso marker="#process_flag_message_queue_data"> @@ -2271,6 +2279,15 @@ os_prompt%</pre> </func> <func> + <name name="iolist_to_iovec" arity="1"/> + <fsummary>Converts an iolist to a iovec.</fsummary> + <desc> + <p>Returns an iovec that is made from the integers and binaries in + <c><anno>IoListOrBinary</anno></c>.</p> + </desc> + </func> + + <func> <name name="is_alive" arity="0"/> <fsummary>Check whether the local node is alive.</fsummary> <desc> diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml index 76aab90e9d..050e84f0c1 100644 --- a/erts/doc/src/notes.xml +++ b/erts/doc/src/notes.xml @@ -603,7 +603,7 @@ marker="erts:erl"><c>erl</c></seealso> command.</p> <p> See <url - href="http://pcre.org/original/changelog.txt"><c>http://pcre.org/original/changelog.txt</c></url> + href="http://pcre.org/original/changelog.txt">http://pcre.org/original/changelog.txt</url> for information about changes made to PCRE between the versions 8.33 and 8.40.</p> <p> diff --git a/erts/doc/src/zlib.xml b/erts/doc/src/zlib.xml index 1d272c4c18..f5cc1b1e64 100644 --- a/erts/doc/src/zlib.xml +++ b/erts/doc/src/zlib.xml @@ -65,13 +65,17 @@ list_to_binary([Compressed|Last])</pre> <tag><c>badarg</c></tag> <item>Bad argument. </item> + <tag><c>not_initialized</c></tag> + <item>The stream hasn't been initialized, eg. if + <seealso marker="#inflateInit/1"><c>inflateInit/1</c></seealso> wasn't + called prior to a call to + <seealso marker="#inflate/2"><c>inflate/2</c></seealso>. + </item> <tag><c>data_error</c></tag> <item>The data contains errors. </item> <tag><c>stream_error</c></tag> <item>Inconsistent stream state.</item> - <tag><c>einval</c></tag> - <item>Bad value or wrong function called.</item> <tag><c>{need_dictionary,Adler32}</c></tag> <item>See <seealso marker="#inflate/2"><c>inflate/2</c></seealso>. </item> @@ -90,6 +94,9 @@ list_to_binary([Compressed|Last])</pre> <name name="zlevel"/> </datatype> <datatype> + <name name="zflush"/> + </datatype> + <datatype> <name name="zmemlevel"/> </datatype> <datatype> @@ -112,6 +119,11 @@ list_to_binary([Compressed|Last])</pre> <fsummary>Calculate the Adler checksum.</fsummary> <desc> <p>Calculates the Adler-32 checksum for <c><anno>Data</anno></c>.</p> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="erts:erlang#adler32/1"> + <c>erlang:adler32/1</c></seealso> instead.</p> + </warning> </desc> </func> @@ -127,6 +139,11 @@ list_to_binary([Compressed|Last])</pre> Crc = lists:foldl(fun(Data,Crc0) -> zlib:adler32(Z, Crc0, Data), end, zlib:adler32(Z,<< >>), Datas)</pre> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="erts:erlang#adler32/2"> + <c>erlang:adler32/2</c></seealso> instead.</p> + </warning> </desc> </func> @@ -141,6 +158,11 @@ Crc = lists:foldl(fun(Data,Crc0) -> <p>This function returns the <c><anno>Adler</anno></c> checksum of <c>[Data1,Data2]</c>, requiring only <c><anno>Adler1</anno></c>, <c><anno>Adler2</anno></c>, and <c><anno>Size2</anno></c>.</p> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="erts:erlang#adler32_combine/3"> + <c>erlang:adler32_combine/3</c></seealso> instead.</p> + </warning> </desc> </func> @@ -165,6 +187,12 @@ Crc = lists:foldl(fun(Data,Crc0) -> <fsummary>Get current CRC.</fsummary> <desc> <p>Gets the current calculated CRC checksum.</p> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="erts:erlang#crc32/1"> + <c>erlang:crc32/1</c></seealso> on the uncompressed data + instead.</p> + </warning> </desc> </func> @@ -173,6 +201,11 @@ Crc = lists:foldl(fun(Data,Crc0) -> <fsummary>Calculate CRC.</fsummary> <desc> <p>Calculates the CRC checksum for <c><anno>Data</anno></c>.</p> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="erts:erlang#crc32/1"> + <c>erlang:crc32/1</c></seealso> instead.</p> + </warning> </desc> </func> @@ -188,6 +221,11 @@ Crc = lists:foldl(fun(Data,Crc0) -> Crc = lists:foldl(fun(Data,Crc0) -> zlib:crc32(Z, Crc0, Data), end, zlib:crc32(Z,<< >>), Datas)</pre> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="erts:erlang#crc32/2"> + <c>erlang:crc32/2</c></seealso> instead.</p> + </warning> </desc> </func> @@ -202,6 +240,11 @@ Crc = lists:foldl(fun(Data,Crc0) -> <p>This function returns the <c><anno>CRC</anno></c> checksum of <c>[Data1,Data2]</c>, requiring only <c><anno>CRC1</anno></c>, <c><anno>CRC2</anno></c>, and <c><anno>Size2</anno></c>.</p> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="erts:erlang#crc32_combine/3"> + <c>erlang:crc32_combine/3</c></seealso> instead.</p> + </warning> </desc> </func> @@ -407,8 +450,8 @@ list_to_binary([B1,B2])</pre> <seealso marker="#deflateInit/1"><c>deflateInit/1,2,6</c></seealso> or <seealso marker="#deflateReset/1"><c>deflateReset/1</c></seealso>, before any call of - <seealso marker="#deflate/3"><c>deflate/3</c></seealso>. - The compressor and decompressor must use the same dictionary (see + <seealso marker="#deflate/3"><c>deflate/3</c></seealso>.</p> + <p>The compressor and decompressor must use the same dictionary (see <seealso marker="#inflateSetDictionary/2"> <c>inflateSetDictionary/2</c></seealso>).</p> <p>The Adler checksum of the dictionary is returned.</p> @@ -420,6 +463,10 @@ list_to_binary([B1,B2])</pre> <fsummary>Get buffer size.</fsummary> <desc> <p>Gets the size of the intermediate buffer.</p> + <warning> + <p>This function is deprecated and will be removed in a future + release.</p> + </warning> </desc> </func> @@ -443,14 +490,31 @@ list_to_binary([B1,B2])</pre> <name name="inflate" arity="2"/> <fsummary>Decompress data.</fsummary> <desc> - <p>Decompresses as much data as possible. - It can introduce some output latency (reading - input without producing any output).</p> - <p>If a preset dictionary is needed at this point (see - <seealso marker="#inflateSetDictionary/2"> - <c>inflateSetDictionary/2</c></seealso>), <c>inflate/2</c> throws a - <c>{need_dictionary,Adler}</c> exception, where <c>Adler</c> is - the Adler-32 checksum of the dictionary chosen by the compressor.</p> + <p>Equivalent to + <seealso marker="#inflate/3"><c>inflate(Z, Data, [])</c></seealso> + </p> + </desc> + </func> + + <func> + <name name="inflate" arity="3"/> + <fsummary>Decompress data.</fsummary> + <desc> + <p>Decompresses as much data as possible. It can introduce some output + latency (reading input without producing any output).</p> + <p>Currently the only available option is + <c>{exception_on_need_dict,boolean()}</c> which controls whether the + function should throw an exception when a preset dictionary is + required for decompression. When set to false, a + <c>need_dictionary</c> tuple will be returned instead. See + <seealso marker="#inflateSetDictionary/2"> + <c>inflateSetDictionary/2</c></seealso> for details.</p> + <warning> + <p>This option defaults to <c>true</c> for backwards compatibility + but we intend to remove the exception behavior in a future + release. New code that needs to handle dictionaries manually + should always specify <c>{exception_on_need_dict,false}</c>.</p> + </warning> </desc> </func> @@ -458,6 +522,11 @@ list_to_binary([B1,B2])</pre> <name name="inflateChunk" arity="1"/> <fsummary>Read next uncompressed chunk.</fsummary> <desc> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="#safeInflate/2"><c>safeInflate/2</c> + </seealso> instead.</p> + </warning> <p>Reads the next chunk of uncompressed data, initialized by <seealso marker="#inflateChunk/2"><c>inflateChunk/2</c></seealso>.</p> <p>This function is to be repeatedly called, while it returns @@ -469,23 +538,27 @@ list_to_binary([B1,B2])</pre> <name name="inflateChunk" arity="2"/> <fsummary>Decompress data with limited output size.</fsummary> <desc> + <warning> + <p>This function is deprecated and will be removed in a future + release. Use <seealso marker="#safeInflate/2"><c>safeInflate/2</c> + </seealso> instead.</p> + </warning> <p>Like <seealso marker="#inflate/2"><c>inflate/2</c></seealso>, - but decompresses no more data than will fit in the buffer configured - through <seealso marker="#setBufSize/2"><c>setBufSize/2</c></seealso>. - Is is useful when decompressing a stream with a high compression - ratio, such that a small amount of compressed input can expand up to - 1000 times.</p> + but decompresses no more data than will fit in the buffer configured + through <seealso marker="#setBufSize/2"><c>setBufSize/2</c> + </seealso>. Is is useful when decompressing a stream with a high + compression ratio, such that a small amount of compressed input can + expand up to 1000 times.</p> <p>This function returns <c>{more, Decompressed}</c>, when there is - more output available, and - <seealso marker="#inflateChunk/1"><c>inflateChunk/1</c></seealso> - is to be used to read it.</p> - <p>This function can introduce some output latency (reading - input without producing any output).</p> - <p>If a preset dictionary is needed at this point (see - <seealso marker="#inflateSetDictionary/2"> - <c>inflateSetDictionary/2</c></seealso>), this function throws a - <c>{need_dictionary,Adler}</c> exception, where <c>Adler</c> is - the Adler-32 checksum of the dictionary chosen by the compressor.</p> + more output available, and + <seealso marker="#inflateChunk/1"><c>inflateChunk/1</c></seealso> + is to be used to read it.</p> + <p>This function can introduce some output latency (reading input + without producing any output).</p> + <p>An exception will be thrown if a preset dictionary is required for + further decompression. See + <seealso marker="#inflateSetDictionary/2"> + <c>inflateSetDictionary/2</c></seealso> for details.</p> <p>Example:</p> <pre> walk(Compressed, Handler) -> @@ -517,6 +590,18 @@ loop(Z, Handler, Uncompressed) -> </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="inflateInit" arity="1"/> <fsummary>Initialize a session for decompression.</fsummary> <desc> @@ -562,45 +647,83 @@ loop(Z, Handler, Uncompressed) -> <fsummary>Initialize the decompression dictionary.</fsummary> <desc> <p>Initializes the decompression dictionary from the specified - uncompressed byte sequence. This function must be called - immediately after a call of - <seealso marker="#inflate/2"><c>inflate/2</c></seealso> - if this call threw a <c>{need_dictionary,Adler}</c> exception. - The dictionary chosen by the compressor can be determined from the - Adler value thrown by the call to <c>inflate/2</c>. - The compressor and decompressor must use the same dictionary (see - <seealso marker="#deflateSetDictionary/2"> - <c>deflateSetDictionary/2</c></seealso>).</p> + uncompressed byte sequence. This function must be called as a + response to an inflate operation (eg. + <seealso marker="#safeInflate/2"><c>safeInflate/2</c></seealso>) + returning <c>{need_dictionary,Adler,Output}</c> or in the case of + deprecated functions, throwing an + <c>{'EXIT',{{need_dictionary,Adler},_StackTrace}}</c> exception.</p> + <p>The dictionary chosen by the compressor can be determined from the + Adler value returned or thrown by the call to the inflate function. + The compressor and decompressor must use the same dictionary (See + <seealso marker="#deflateSetDictionary/2"> + <c>deflateSetDictionary/2</c></seealso>).</p> + <p>After setting the dictionary the inflate operation should be + retried without new input.</p> <p>Example:</p> <pre> -unpack(Z, Compressed, Dict) -> +deprecated_unpack(Z, Compressed, Dict) -> case catch zlib:inflate(Z, Compressed) of - {'EXIT',{{need_dictionary,DictID},_}} -> - zlib:inflateSetDictionary(Z, Dict), + {'EXIT',{{need_dictionary,_DictID},_}} -> + ok = zlib:inflateSetDictionary(Z, Dict), Uncompressed = zlib:inflate(Z, []); Uncompressed -> Uncompressed - end.</pre> + end. + +new_unpack(Z, Compressed, Dict) -> + case zlib:inflate(Z, Compressed, [{exception_on_need_dict, false}]) of + {need_dictionary, _DictId, Output} -> + ok = zlib:inflateSetDictionary(Z, Dict), + [Output | zlib:inflate(Z, [])]; + Uncompressed -> + Uncompressed + end.</pre> </desc> </func> <func> - <name name="inflateGetDictionary" arity="1"/> - <fsummary>Return the decompression dictionary.</fsummary> + <name name="open" arity="0"/> + <fsummary>Open a stream and return a stream reference.</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> + <p>Opens a zlib stream.</p> </desc> </func> <func> - <name name="open" arity="0"/> - <fsummary>Open a stream and return a stream reference.</fsummary> + <name name="safeInflate" arity="2"/> + <fsummary>Decompress data with limited output size.</fsummary> <desc> - <p>Opens a zlib stream.</p> + <p>Like <seealso marker="#inflate/2"><c>inflate/2</c></seealso>, + but returns once it has expanded beyond a small + implementation-defined threshold. It's useful when decompressing + untrusted input which could have been maliciously crafted to expand + until the system runs out of memory.</p> + <p>This function returns <c>{continue | finished, Output}</c>, where + <anno>Output</anno> is the data that was decompressed in this call. + New input can be queued up on each call if desired, and the function + will return <c>{finished, Output}</c> once all queued data has been + decompressed.</p> + <p>This function can introduce some output latency (reading + input without producing any output).</p> + <p>If a preset dictionary is required for further decompression, this + function returns a <c>need_dictionary</c> tuple. See + <seealso marker="#inflateSetDictionary/2"> + <c>inflateSetDictionary/2</c></seealso>) for details.</p> + <p>Example:</p> + <pre> +walk(Compressed, Handler) -> + Z = zlib:open(), + zlib:inflateInit(Z), + loop(Z, Handler, zlib:safeInflate(Z, Compressed)), + zlib:inflateEnd(Z), + zlib:close(Z). + +loop(Z, Handler, {continue, Output}) -> + Handler(Output), + loop(Z, Handler, zlib:safeInflate(Z, [])); +loop(Z, Handler, {finished, Output}) -> + Handler(Output).</pre> </desc> </func> @@ -609,6 +732,10 @@ unpack(Z, Compressed, Dict) -> <fsummary>Set buffer size.</fsummary> <desc> <p>Sets the intermediate buffer size.</p> + <warning> + <p>This function is deprecated and will be removed in a future + release.</p> + </warning> </desc> </func> |