Take a temporary copy of buffers provided as input. Soak testing suggests this prevents the problems seen in #6.

README.md

@@ -9,9 +9,9 @@ _adj_
 
 The typical use case for this high speed Node.js module is to convert large JPEG and PNG images to smaller JPEG and PNG images of varying dimensions.
 
-Under the hood you'll find the blazingly fast [libvips](https://github.com/jcupitt/libvips) image processing library, originally created in 1989 at Birkbeck College and currently maintained by John Cupitt.
+The performance of JPEG resizing is typically 15x-25x faster than ImageMagick and GraphicsMagick, based mainly on the number of CPU cores available.
 
-Performance is up to 18x faster than ImageMagick and up to 8x faster than GraphicsMagick, based mainly on the number of CPU cores available.
+Under the hood you'll find the blazingly fast [libvips](https://github.com/jcupitt/libvips) image processing library, originally created in 1989 at Birkbeck College and currently maintained by John Cupitt.
 
 ## Prerequisites
 
@@ -119,35 +119,35 @@ Test environment:
 
 ### JPEG
 
-* imagemagick x 5.50 ops/sec ±0.48% (31 runs sampled)
-* gm-file-file x 11.19 ops/sec ±0.51% (57 runs sampled)
-* gm-file-buffer x 11.11 ops/sec ±0.42% (57 runs sampled)
-* epeg-file-file x 28.59 ops/sec ±0.09% (71 runs sampled)
-* epeg-file-buffer x 28.67 ops/sec ±0.14% (71 runs sampled)
+* imagemagick x 5.53 ops/sec ±0.62% (31 runs sampled)
+* gm-file-file x 4.10 ops/sec ±0.41% (25 runs sampled)
+* gm-file-buffer x 4.10 ops/sec ±0.36% (25 runs sampled)
+* epeg-file-file x 23.82 ops/sec ±0.18% (60 runs sampled)
+* epeg-file-buffer x 23.98 ops/sec ±0.16% (61 runs sampled)
 
-* sharp-buffer-file x 24.72 ops/sec ±0.42% (62 runs sampled)
-* sharp-buffer-buffer x 24.24 ops/sec ±0.36% (61 runs sampled)
-* sharp-file-file x 97.15 ops/sec ±0.44% (80 runs sampled)
-* sharp-file-buffer x __98.51 ops/sec__ ±0.42% (80 runs sampled)
+* sharp-buffer-file x 20.76 ops/sec ±0.55% (54 runs sampled)
+* sharp-buffer-buffer x 20.90 ops/sec ±0.26% (54 runs sampled)
+* sharp-file-file x 91.78 ops/sec ±0.38% (88 runs sampled)
+* sharp-file-buffer x __93.05 ops/sec__ ±0.61% (76 runs sampled)
 
-* sharp-file-buffer-sharpen x 56.99 ops/sec ±5.43% (57 runs sampled)
-* sharp-file-buffer-progressive x 64.89 ops/sec ±0.42% (79 runs sampled)
-* sharp-file-buffer-sequentialRead x 64.13 ops/sec ±0.40% (78 runs sampled)
+* sharp-file-buffer-sharpen x 63.09 ops/sec ±5.58% (63 runs sampled)
+* sharp-file-buffer-progressive x 61.68 ops/sec ±0.53% (76 runs sampled)
+* sharp-file-buffer-sequentialRead x 60.66 ops/sec ±0.38% (75 runs sampled)
 
 ### PNG
 
-* imagemagick x 4.31 ops/sec ±0.27% (26 runs sampled)
-* gm-file-file x 17.89 ops/sec ±0.21% (86 runs sampled)
-* gm-file-buffer x 14.74 ops/sec ±0.15% (73 runs sampled)
+* imagemagick x 4.27 ops/sec ±0.21% (25 runs sampled)
+* gm-file-file x 8.33 ops/sec ±0.19% (44 runs sampled)
+* gm-file-buffer x 7.45 ops/sec ±0.16% (40 runs sampled)
  
-* sharp-buffer-file x 4.97 ops/sec ±120.47% (26 runs sampled)
-* sharp-buffer-buffer x 13.00 ops/sec ±0.53% (65 runs sampled)
-* sharp-file-file x 53.00 ops/sec ±7.15% (88 runs sampled)
-* sharp-file-buffer x __55.43 ops/sec__ ±0.65% (89 runs sampled)
- 
-* sharp-file-buffer-sharpen x 45.37 ops/sec ±0.38% (74 runs sampled)
-* sharp-file-buffer-progressive x 55.49 ops/sec ±0.45% (89 runs sampled)
-* sharp-file-buffer-sequentialRead x 32.27 ops/sec ±0.29% (79 runs sampled)
+* sharp-buffer-file x 4.94 ops/sec ±118.46% (26 runs sampled)
+* sharp-buffer-buffer x 12.59 ops/sec ±0.55% (64 runs sampled)
+* sharp-file-file x 44.06 ops/sec ±6.86% (75 runs sampled)
+* sharp-file-buffer x __46.29 ops/sec__ ±0.38% (76 runs sampled)
+
+* sharp-file-buffer-sharpen x 38.86 ops/sec ±0.22% (65 runs sampled)
+* sharp-file-buffer-progressive x 46.35 ops/sec ±0.20% (76 runs sampled)
+* sharp-file-buffer-sequentialRead x 29.02 ops/sec ±0.62% (72 runs sampled)
 
 ## Licence
 

binding.gyp

@@ -7,11 +7,13 @@
       '<!@(PKG_CONFIG_PATH="/usr/lib/pkgconfig" pkg-config --libs vips)'
     ],
     'include_dirs': [
+      '/usr/local/include/glib-2.0',
+      '/usr/local/lib/glib-2.0/include',
       '/usr/include/glib-2.0',
       '/usr/lib/glib-2.0/include',
       '/usr/lib/x86_64-linux-gnu/glib-2.0/include'
     ],
-    'cflags': ['-fexceptions', '-O3'],
-    'cflags_cc': ['-fexceptions', '-O3']
+    'cflags': ['-fexceptions', '-pedantic', '-Wall', '-O3'],
+    'cflags_cc': ['-fexceptions', '-pedantic', '-Wall', '-O3']
   }]
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sharp",
-  "version": "0.1.0",
+  "version": "0.1.5",
   "author": "Lovell Fuller",
   "description": "High performance module to resize JPEG and PNG images using the libvips image processing library",
   "scripts": {

src/sharp.cc

@@ -18,7 +18,7 @@ struct resize_baton {
   int  width;
   int  height;
   bool crop;
-  int  embed;
+  VipsExtend extend;
   bool sharpen;
   bool progessive;
   VipsAccess access_method;
@@ -98,66 +98,80 @@ void resize_async(uv_work_t *work) {
   int shrink_on_load = 1;
   if (inputImageType == JPEG) {
     if (shrink >= 8) {
-      residual = residual * shrink / 8;
+      factor = factor / 8;
       shrink_on_load = 8;
-      shrink = 1;
     } else if (shrink >= 4) {
-      residual = residual * shrink / 4;
+      factor = factor / 4;
       shrink_on_load = 4;
-      shrink = 1;
     } else if (shrink >= 2) {
-      residual = residual * shrink / 2;
+      factor = factor / 2;
       shrink_on_load = 2;
-      shrink = 1;
-    }
-    if (shrink_on_load > 1) {
-      g_object_unref(in);
-      in = vips_image_new();
-      if (baton->buffer_in_len > 1) {
-        if (vips_jpegload_buffer(baton->buffer_in, baton->buffer_in_len, &in, "shrink", shrink_on_load, NULL)) {
-          return resize_error(baton, in);
-        }
-      } else {
-        if (vips_jpegload((baton->file_in).c_str(), &in, "shrink", shrink_on_load, NULL)) {
-          return resize_error(baton, in);
-        }
-      }
     }
   }
+  VipsImage *shrunk_on_load = vips_image_new();
+  if (shrink_on_load > 1) {
+    // Recalculate integral shrink and double residual
+    factor = std::max(factor, 1.0);
+    shrink = floor(factor);
+    residual = shrink / factor;
+    // Reload input using shrink-on-load 
+    if (baton->buffer_in_len > 1) {
+      if (vips_jpegload_buffer(baton->buffer_in, baton->buffer_in_len, &shrunk_on_load, "shrink", shrink_on_load, NULL)) {
+        return resize_error(baton, in);
+      }
+    } else {
+      if (vips_jpegload((baton->file_in).c_str(), &shrunk_on_load, "shrink", shrink_on_load, NULL)) {
+        return resize_error(baton, in);
+      }
+    }
+  } else {
+    vips_copy(in, &shrunk_on_load, NULL);
+  }
+  g_object_unref(in);
 
   VipsImage *shrunk = vips_image_new();
   if (shrink > 1) {
     // Use vips_shrink with the integral reduction
-    if (vips_shrink(in, &shrunk, shrink, shrink, NULL)) {
-      return resize_error(baton, in);
+    if (vips_shrink(shrunk_on_load, &shrunk, shrink, shrink, NULL)) {
+      return resize_error(baton, shrunk_on_load);
     }
   } else {
-    vips_copy(in, &shrunk, NULL);
+    vips_copy(shrunk_on_load, &shrunk, NULL);
   }
-  g_object_unref(in);
+  g_object_unref(shrunk_on_load);
 
   // Use vips_affine with the remaining float part using bilinear interpolation
   VipsImage *affined = vips_image_new();
-  if (vips_affine(shrunk, &affined, residual, 0, 0, residual, "interpolate", vips_interpolate_bilinear_static(), NULL)) {
-    return resize_error(baton, shrunk);
+  if (residual > 0) {
+    if (vips_affine(shrunk, &affined, residual, 0, 0, residual, "interpolate", vips_interpolate_bilinear_static(), NULL)) {
+      return resize_error(baton, shrunk);
+    }
+  } else {
+    vips_copy(shrunk, &affined, NULL);
   }
   g_object_unref(shrunk);
 
   VipsImage *canvased = vips_image_new();
-  if (baton->crop) {
-    int width = std::min(affined->Xsize, baton->width);
-    int height = std::min(affined->Ysize, baton->height);
-    int left = (affined->Xsize - width + 1) / 2;
-    int top = (affined->Ysize - height + 1) / 2;
-    if (vips_extract_area(affined, &canvased, left, top, width, height, NULL)) {
-      return resize_error(baton, affined);
+  if (affined->Xsize != baton->width || affined->Ysize != baton->height) {
+    if (baton->crop) {
+      // Crop
+      int width = std::min(affined->Xsize, baton->width);
+      int height = std::min(affined->Ysize, baton->height);
+      int left = (affined->Xsize - width + 1) / 2;
+      int top = (affined->Ysize - height + 1) / 2;
+      if (vips_extract_area(affined, &canvased, left, top, width, height, NULL)) {
+        return resize_error(baton, affined);
+      }
+    } else {
+      // Embed
+      int left = (baton->width - affined->Xsize) / 2;
+      int top = (baton->height - affined->Ysize) / 2;
+      if (vips_embed(affined, &canvased, left, top, baton->width, baton->height, "extend", baton->extend, NULL)) {
+        return resize_error(baton, affined);
+      }
     }
   } else {
-    int left = (baton->width - affined->Xsize) / 2;
-    int top = (baton->height - affined->Ysize) / 2;
-    if (vips_embed(affined, &canvased, baton->embed, left, top, baton->width, baton->height, NULL)) {
-      return resize_error(baton, affined);
-    }
+    vips_copy(affined, &canvased, NULL);
   }
   g_object_unref(affined);
 
@@ -179,28 +193,28 @@ void resize_async(uv_work_t *work) {
 
   if (baton->file_out == "__jpeg") {
     // Write JPEG to buffer
-    if (vips_jpegsave_buffer(canvased, &baton->buffer_out, &baton->buffer_out_len, "strip", TRUE, "Q", 80, "optimize_coding", TRUE, "interlace", baton->progessive, NULL)) {
-      return resize_error(baton, canvased);
+    if (vips_jpegsave_buffer(sharpened, &baton->buffer_out, &baton->buffer_out_len, "strip", TRUE, "Q", 80, "optimize_coding", TRUE, "interlace", baton->progessive, NULL)) {
+      return resize_error(baton, sharpened);
     }
   } else if (baton->file_out == "__png") {
     // Write PNG to buffer
-    if (vips_pngsave_buffer(canvased, &baton->buffer_out, &baton->buffer_out_len, "strip", TRUE, "compression", 6, "interlace", baton->progessive, NULL)) {
-      return resize_error(baton, canvased);
+    if (vips_pngsave_buffer(sharpened, &baton->buffer_out, &baton->buffer_out_len, "strip", TRUE, "compression", 6, "interlace", baton->progessive, NULL)) {
+      return resize_error(baton, sharpened);
     }
   } else if (is_jpeg(baton->file_out))  {
     // Write JPEG to file
-    if (vips_jpegsave(canvased, baton->file_out.c_str(), "strip", TRUE, "Q", 80, "optimize_coding", TRUE, "interlace", baton->progessive, NULL)) {
-      return resize_error(baton, canvased);
+    if (vips_jpegsave(sharpened, baton->file_out.c_str(), "strip", TRUE, "Q", 80, "optimize_coding", TRUE, "interlace", baton->progessive, NULL)) {
+      return resize_error(baton, sharpened);
     }
   } else if (is_png(baton->file_out)) {
     // Write PNG to file
-    if (vips_pngsave(canvased, baton->file_out.c_str(), "strip", TRUE, "compression", 6, "interlace", baton->progessive, NULL)) {
-      return resize_error(baton, canvased);
+    if (vips_pngsave(sharpened, baton->file_out.c_str(), "strip", TRUE, "compression", 6, "interlace", baton->progessive, NULL)) {
+      return resize_error(baton, sharpened);
     }
   } else {
     (baton->err).append("Unsupported output " + baton->file_out);
   }
-  g_object_unref(canvased);
+  g_object_unref(sharpened);
   vips_thread_shutdown();
 }
 
@@ -209,10 +223,15 @@ void resize_async_after(uv_work_t *work, int status) {
 
   resize_baton *baton = static_cast<resize_baton*>(work->data);
 
+  // Free temporary copy of input buffer
+  if (baton->buffer_in_len > 0) {
+    g_free(baton->buffer_in);
+  }
+
   Handle<Value> argv[2] = { Null(), Null() };
   if (!baton->err.empty()) {
     // Error
-    argv[0] = String::New(baton->err.data(), baton->err.size());
+    argv[0] = scope.Close(String::New(baton->err.data(), baton->err.size()));
   } else if (baton->buffer_out_len > 0) {
     // Buffer
     Buffer *slowBuffer = Buffer::New(baton->buffer_out_len);
@@ -220,7 +239,7 @@ void resize_async_after(uv_work_t *work, int status) {
     Local<Object> globalObj = Context::GetCurrent()->Global();
     Local<Function> bufferConstructor = Local<Function>::Cast(globalObj->Get(String::New("Buffer")));
     Handle<Value> constructorArgs[3] = { slowBuffer->handle_, v8::Integer::New(baton->buffer_out_len), v8::Integer::New(0) };
-    argv[1] = bufferConstructor->NewInstance(3, constructorArgs);
+    argv[1] = scope.Close(bufferConstructor->NewInstance(3, constructorArgs));
     g_free(baton->buffer_out);
   }
 
@@ -237,8 +256,12 @@ Handle<Value> resize(const Arguments& args) {
   baton->file_in = *String::Utf8Value(args[0]->ToString());
   if (args[1]->IsObject()) {
     Local<Object> buffer = args[1]->ToObject();
-    baton->buffer_in = Buffer::Data(buffer);
-    baton->buffer_in_len = Buffer::Length(buffer);
+    // Take temporary copy of input buffer
+    if (Buffer::Length(buffer) > 0) {
+      baton->buffer_in_len = Buffer::Length(buffer);
+      baton->buffer_in = g_malloc(baton->buffer_in_len);
+      memcpy(baton->buffer_in, Buffer::Data(buffer), baton->buffer_in_len);
+    }
   }
   baton->file_out = *String::Utf8Value(args[2]->ToString());
   baton->width = args[3]->Int32Value();
@@ -248,10 +271,10 @@ Handle<Value> resize(const Arguments& args) {
     baton->crop = true;
   } else if (canvas->Equals(String::NewSymbol("w"))) {
     baton->crop = false;
-    baton->embed = 4;
+    baton->extend = VIPS_EXTEND_WHITE;
   } else if (canvas->Equals(String::NewSymbol("b"))) {
     baton->crop = false;
-    baton->embed = 0;
+    baton->extend = VIPS_EXTEND_BLACK;
   }
   baton->sharpen = args[6]->BooleanValue();
   baton->progessive = args[7]->BooleanValue();
@@ -274,6 +297,6 @@ extern "C" void init(Handle<Object> target) {
   vips_init("");
   AtExit(at_exit);
   NODE_SET_METHOD(target, "resize", resize);
-};
+}
 
-NODE_MODULE(sharp, init);
+NODE_MODULE(sharp, init)

tests/parallel.js

@@ -0,0 +1,29 @@
+var sharp = require("../index");
+var fs = require("fs");
+var assert = require("assert");
+var async = require("async");
+
+var inputJpg = __dirname + "/2569067123_aca715a2ee_o.jpg"; // http://www.flickr.com/photos/grizdave/2569067123/
+var width = 720;
+var height = 480;
+
+async.mapSeries([1, 1, 2, 4, 8, 16, 32, 64, 128], function(parallelism, next) {
+  var start = new Date().getTime();
+  async.times(parallelism,
+    function(id, callback) {
+      sharp.resize(inputJpg, sharp.buffer.jpeg, width, height, function(err, buffer) {
+        buffer = null;
+        callback(err, new Date().getTime() - start);
+      });
+    },
+    function(err, ids) {
+      assert(!err);
+      assert(ids.length === parallelism);
+      var mean = ids.reduce(function(a, b) {
+        return a + b;
+      }) / ids.length;
+      console.log(parallelism + " parallel calls: fastest=" + ids[0] + "ms slowest=" + ids[ids.length - 1] + "ms mean=" + mean + "ms");
+      next();
+    }
+  );
+}, function() {});

tests/perf.js

@@ -13,7 +13,7 @@ var outputJpg = __dirname + "/output.jpg";
 var inputPng = __dirname + "/50020484-00001.png"; // http://c.searspartsdirect.com/lis_png/PLDM/50020484-00001.png
 var outputPng = __dirname + "/output.png";
 
-var width = 640;
+var width = 720;
 var height = 480;
 
 async.series({
@@ -39,7 +39,7 @@ async.series({
     }).add("gm-file-file", {
       defer: true,
       fn: function(deferred) {
-        gm(inputJpg).crop(width, height).quality(80).write(outputJpg, function (err) {
+        gm(inputJpg).resize(width, height).quality(80).write(outputJpg, function (err) {
           if (err) {
             throw err;
           } else {
@@ -50,7 +50,7 @@ async.series({
     }).add("gm-file-buffer", {
       defer: true,
       fn: function(deferred) {
-        gm(inputJpg).crop(width, height).quality(80).toBuffer(function (err, buffer) {
+        gm(inputJpg).resize(width, height).quality(80).toBuffer(function (err, buffer) {
           if (err) {
             throw err;
           } else {
@@ -183,7 +183,7 @@ async.series({
     }).add("gm-file-file", {
       defer: true,
       fn: function(deferred) {
-        gm(inputPng).crop(width, height).write(outputPng, function (err) {
+        gm(inputPng).resize(width, height).write(outputPng, function (err) {
           if (err) {
             throw err;
           } else {
@@ -194,7 +194,7 @@ async.series({
     }).add("gm-file-buffer", {
       defer: true,
       fn: function(deferred) {
-        gm(inputPng).crop(width, height).quality(80).toBuffer(function (err, buffer) {
+        gm(inputPng).resize(width, height).quality(80).toBuffer(function (err, buffer) {
           if (err) {
             throw err;
           } else {