Add incremental zstd_(un)compress_init() and zstd_(un)compress_add()

README.md

@@ -104,6 +104,11 @@ LIBZSTD\_VERSION\_STRING       | libzstd version string
 * zstd\_uncompress — Zstandard decompression
 * zstd\_compress\_dict — Zstandard compression using a digested dictionary
 * zstd\_uncompress\_dict — Zstandard decompression using a digested dictionary
+* zstd\_compress\_init — Initialize an incremental compress context
+* zstd\_compress\_add — Incrementally compress data
+* zstd\_uncompress\_init — Initialize an incremental uncompress context
+* zstd\_uncompress\_add — Incrementally uncompress data
+
 
 ### zstd\_compress — Zstandard compression
 
@@ -209,6 +214,88 @@ Zstandard decompression using a digested dictionary.
 Returns the decompressed data or FALSE if an error occurred.
 
 
+### zstd\_compress\_init — Initialize an incremental compress context
+
+#### Description
+
+resource **zstd\_compress\_init** ( [ int _$level_ = ZSTD_COMPRESS_LEVEL_DEFAULT ] )
+
+Initialize an incremental compress context
+
+#### Parameters
+
+* _level_
+
+  The higher the level, the slower the compression. (Defaults to `ZSTD_COMPRESS_LEVEL_DEFAULT`)
+
+#### Return Values
+
+Returns a zstd context instance on success, or FALSE on failure
+
+
+### zstd\_compress\_add — Incrementally compress data
+
+#### Description
+
+string **zstd\_compress\_add** ( ZstdContext _$context_, string _$data_ [, bool _$end_ = false ] )
+
+Incrementally compress data
+
+#### Parameters
+
+* _context_
+
+  A context created with `zstd_compress_init()`.
+
+* _data_
+
+  A chunk of data to compress.
+
+* _end_
+
+  Set to true to terminate with the last chunk of data.
+
+#### Return Values
+
+Returns a chunk of compressed data, or FALSE on failure.
+
+
+### zstd\_uncompress\_init — Initialize an incremental uncompress context
+
+#### Description
+
+resource **zstd\_uncompress\_init** ( void )
+
+Initialize an incremental uncompress context
+
+#### Return Values
+
+Returns a zstd context instance on success, or FALSE on failure
+
+
+### zstd\_uncompress\_add — Incrementally uncompress data
+
+#### Description
+
+string **zstd\_uncompress\_add** ( ZstdContext _$context_, string _$data_ )
+
+Incrementally uncompress data
+
+#### Parameters
+
+* _context_
+
+  A context created with `zstd_uncompress_init()`.
+
+* _data_
+
+  A chunk of compressed data.
+
+#### Return Values
+
+Returns a chunk of uncompressed data, or FALSE on failure.
+
+
 ## Namespace
 
 ```
@@ -218,10 +305,16 @@ function compress( $data [, $level = 3 ] )
 function uncompress( $data )
 function compress_dict ( $data, $dict )
 function uncompress_dict ( $data, $dict )
+function compress_init ( [ $level = 3 ] )
+function compress_add ( $context, $data [, $end = false ] )
+function uncompress_init ()
+function uncompress_add ( $context, $data )
+
 ```
 
-`zstd_compress`, `zstd_uncompress`, `zstd_compress_dict` and
-`zstd_uncompress_dict` function alias.
+`zstd_compress`, `zstd_uncompress`, `zstd_compress_dict`,
+`zstd_uncompress_dict`, `zstd_compress_init`, `zstd_compress_add`,
+`zstd_uncompress_init` and `zstd_uncompress_add` function aliases.
 
 ## Streams
 

tests/inc.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Incremental compression and decompression
+--FILE--
+<?php
+
+// compression
+$resource = zstd_compress_init();
+$compressed = '';
+$compressed .= zstd_compress_add($resource, 'Hello, ', false);
+$compressed .= zstd_compress_add($resource, 'World!', false);
+$compressed .= zstd_compress_add($resource, '', true);
+
+echo zstd_uncompress($compressed), PHP_EOL;
+
+// uncompression
+$resource = zstd_uncompress_init();
+$uncompressed = '';
+$uncompressed .= zstd_uncompress_add($resource, substr($compressed, 0, 5));
+$uncompressed .= zstd_uncompress_add($resource, substr($compressed, 5));
+
+echo $uncompressed, PHP_EOL;
+?>
+===Done===
+--EXPECTF--
+Hello, World!
+Hello, World!
+===Done===

tests/inc_comp.phpt

@@ -0,0 +1,45 @@
+--TEST--
+Incremental compression
+--FILE--
+<?php
+include(dirname(__FILE__) . '/data.inc');
+
+foreach ([128, 512, 1024] as $size) {
+  var_dump($size);
+  $handle = zstd_compress_init();
+  var_dump($handle);
+
+  $pos= 0;
+  $compressed = '';
+  while ($pos < strlen($data)) {
+    $chunk = substr($data, $pos, $size);
+    $compressed .= zstd_compress_add($handle, $chunk, false);
+    $pos += strlen($chunk);
+  }
+  $compressed .= zstd_compress_add($handle, '', true);
+  var_dump(strlen($compressed), strlen($compressed) < strlen($data));
+
+  var_dump($data === zstd_uncompress($compressed));
+}
+?>
+===Done===
+--EXPECTF--
+int(128)
+object(ZstdContext)#%d (0) {
+}
+int(%d)
+bool(true)
+bool(true)
+int(512)
+object(ZstdContext)#%d (0) {
+}
+int(%d)
+bool(true)
+bool(true)
+int(1024)
+object(ZstdContext)#%d (0) {
+}
+int(%d)
+bool(true)
+bool(true)
+===Done===

tests/inc_decomp.phpt

@@ -0,0 +1,39 @@
+--TEST--
+Incremental decompression
+--FILE--
+<?php
+include(dirname(__FILE__) . '/data.inc');
+
+$compressed = zstd_compress($data);
+
+foreach ([128, 512, 1024] as $size) {
+  var_dump($size);
+  $handle = zstd_uncompress_init();
+  var_dump($handle);
+
+  $pos= 0;
+  $uncompressed = '';
+  while ($pos < strlen($compressed)) {
+    $chunk = substr($compressed, $pos, $size);
+    $uncompressed .= zstd_uncompress_add($handle, $chunk);
+    $pos += strlen($chunk);
+  }
+
+  var_dump($data === $uncompressed);
+}
+?>
+===Done===
+--EXPECTF--
+int(128)
+object(ZstdContext)#%d (0) {
+}
+bool(true)
+int(512)
+object(ZstdContext)#%d (0) {
+}
+bool(true)
+int(1024)
+object(ZstdContext)#%d (0) {
+}
+bool(true)
+===Done===

tests/inc_ns.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Incremental compression and decompression (namespaces)
+--FILE--
+<?php
+
+// compression
+$resource = \Zstd\compress_init();
+$compressed = '';
+$compressed .= \Zstd\compress_add($resource, 'Hello, ', false);
+$compressed .= \Zstd\compress_add($resource, 'World!', false);
+$compressed .= \Zstd\compress_add($resource, '', true);
+
+echo \Zstd\uncompress($compressed), PHP_EOL;
+
+// uncompression
+$resource = \Zstd\uncompress_init();
+$uncompressed = '';
+$uncompressed .= \Zstd\uncompress_add($resource, substr($compressed, 0, 5));
+$uncompressed .= \Zstd\uncompress_add($resource, substr($compressed, 5));
+
+echo $uncompressed, PHP_EOL;
+?>
+===Done===
+--EXPECTF--
+Hello, World!
+Hello, World!
+===Done===