add streaming-custom example

See #191

Author: jcupitt

CHANGELOG.md

@@ -4,10 +4,14 @@ All notable changes to `:vips` will be documented in this file.
 
 ## master
 
-- improve FFI startup [West14]
+- improve FFI startup [West14, jcupitt]
 - revise example use of composer [jcupitt]
 - fix bandrank [axkirillov]
 - fix FFI startup log error [ganicus]
+- add Source, Target, SourceResource, TargetResource, SourceCustom, 
+  TargetCustom [L3tum]
+- add setProgress and progress example [jcupitt]
+- add streaming-custom example [jcupitt]
 
 ## 2.1.1 - 2022-11-13
 

examples/streaming-custom.php

@@ -0,0 +1,56 @@
+#!/usr/bin/env php
+<?php
+
+require dirname(__DIR__) . '/vendor/autoload.php';
+
+use Jcupitt\Vips;
+
+if (count($argv) != 4) {
+    echo "usage: $argv[0] IN-FILE OUT-FILE FORMAT\n";
+    echo "  eg.: $argv[0] ~/pics/k2.jpg x.tif .tif[tile,pyramid]\n";
+    exit(1);
+}
+    
+$in_file = fopen($argv[1], 'r');
+$source = new Vips\SourceCustom();
+$source->onRead(function ($bufferLength) use (&$in_file) {
+    // return 0 for EOF, -ve for read error
+    return fread($in_file, $bufferLength);
+});
+// seek is optional
+$source->onSeek(function ($offset, $whence) use (&$in_file) {
+    if (fseek($in_file, $offset, $whence)) {
+        return -1;
+    }
+    
+    return ftell($in_file);
+});
+
+// open for write and read ... formats like tiff need to be able to seek back
+// in the output and update bytes later 
+$out_file = fopen($argv[2], 'w+');
+$target = new Vips\TargetCustom();
+$target->onWrite(function ($buffer) use (&$out_file) {
+    $result = fwrite($out_file, $buffer);
+    if ($result === false) {
+        // IO error
+        return -1;
+    }
+    else
+        return $result;
+});
+// read and seek are optional
+$target->onSeek(function ($offset, $whence) use (&$out_file) {
+    if (fseek($out_file, $offset, $whence)) {
+        return -1;
+    }
+
+    return ftell($out_file);
+});
+$target->onRead(function ($bufferLength) use (&$out_file) {
+    return fread($out_file, $bufferLength);
+});
+
+$image = Vips\Image::newFromSource($source);
+$image->writeToTarget($target, $argv[3]);
+

src/GObject.php

@@ -151,7 +151,7 @@ private static function getMarshaler(string $name, callable $callback): ?Closure
                         CData  $hint,
                         ?CData $data
                     ) use (&$callback): void {
-                        assert($numberOfParams === 4);
+                        assert($numberOfParams === 3);
                         /*
                          * Signature: gint64(VipsSourceCustom* source, void* buffer, gint64 length, void* handle)
                          */
@@ -179,7 +179,7 @@ private static function getMarshaler(string $name, callable $callback): ?Closure
                         CData  $hint,
                         ?CData $data
                     ) use (&$callback): void {
-                        assert($numberOfParams === 4);
+                        assert($numberOfParams === 3);
                         /*
                          * Signature: gint64(VipsSourceCustom* source, gint64 offset, int whence, void* handle)
                          */
@@ -200,7 +200,7 @@ private static function getMarshaler(string $name, callable $callback): ?Closure
                         CData  $hint,
                         ?CData $data
                     ) use (&$callback): void {
-                        assert($numberOfParams === 4);
+                        assert($numberOfParams === 3);
                         /*
                          * Signature: gint64(VipsTargetCustom* target, void* buffer, gint64 length, void* handle)
                          */
@@ -223,7 +223,7 @@ private static function getMarshaler(string $name, callable $callback): ?Closure
                         CData  $hint,
                         ?CData $data
                     ) use (&$callback): void {
-                        assert($numberOfParams === 2);
+                        assert($numberOfParams === 0);
                         /**
                          * Signature: void(VipsTargetCustom* target, void* handle)
                          */
@@ -242,7 +242,7 @@ private static function getMarshaler(string $name, callable $callback): ?Closure
                         CData  $hint,
                         ?CData $data
                     ) use (&$callback): void {
-                        assert($numberOfParams === 2);
+                        assert($numberOfParams === 0);
                         /**
                          * Signature: int(VipsTargetCustom* target, void* handle)
                          */