Add Media Type to metadata response #4492

As of 8.18.0, libvips C++ wrapper retrieves error messages at
exception construction time rather than lazily when accessed.

On Windows this led to error messages being referenced rather
than copied, leading to access beyond their lifetime and possible
corruption.

docs/src/content/docs/api-input.md

@@ -18,6 +18,7 @@ Dimensions in the response will respect the `page` and `pages` properties of the
 A `Promise` is returned when `callback` is not provided.
 
 - `format`: Name of decoder used to parse image e.g. `jpeg`, `png`, `webp`, `gif`, `svg`, `heif`, `tiff`
+- `mediaType`: Media Type (MIME Type) e.g. `image/jpeg`, `image/png`, `image/svg+xml`, `image/avif`
 - `size`: Total size of image in bytes, for Stream and Buffer input only
 - `width`: Number of pixels wide (EXIF orientation is not taken into consideration, see example below)
 - `height`: Number of pixels high (EXIF orientation is not taken into consideration, see example below)

docs/src/content/docs/changelog/v0.35.0.md

@@ -20,7 +20,7 @@ slug: changelog/v0.35.0
 
 * Upgrade to libvips v8.18.0 for upstream bug fixes.
 
-* Improve thread-safety of error (and warning) messages.
+* Ensure TIFF output `bitdepth` option is limited to 1, 2 or 4.
 
 * Deprecate Windows 32-bit (win32-ia32) prebuilt binaries.
 
@@ -43,4 +43,7 @@ slug: changelog/v0.35.0
 * Ensure HEIF primary item is used as default page/frame.
   [#4487](https://github.com/lovell/sharp/issues/4487)
 
+* Add image Media Type (MIME Type) to metadata response.
+  [#4492](https://github.com/lovell/sharp/issues/4492)
+
 * Add WebP `exact` option for control over transparent pixel colour values.

lib/index.d.ts

@@ -1479,8 +1479,8 @@ declare namespace sharp {
         xres?: number | undefined;
         /** Vertical resolution in pixels/mm (optional, default 1.0) */
         yres?: number | undefined;
-        /** Reduce bitdepth to 1, 2 or 4 bit (optional, default 8) */
-        bitdepth?: 1 | 2 | 4 | 8 | undefined;
+        /** Reduce bitdepth to 1, 2 or 4 bit (optional) */
+        bitdepth?: 1 | 2 | 4 | undefined;
         /** Write 1-bit images as miniswhite (optional, default false) */
         miniswhite?: boolean | undefined;
         /** Resolution unit options: inch, cm (optional, default 'inch') */

lib/input.js

@@ -567,6 +567,7 @@ function _isStreamInput () {
  * A `Promise` is returned when `callback` is not provided.
  *
  * - `format`: Name of decoder used to parse image e.g. `jpeg`, `png`, `webp`, `gif`, `svg`, `heif`, `tiff`
+ * - `mediaType`: Media Type (MIME Type) e.g. `image/jpeg`, `image/png`, `image/svg+xml`, `image/avif`
  * - `size`: Total size of image in bytes, for Stream and Buffer input only
  * - `width`: Number of pixels wide (EXIF orientation is not taken into consideration, see example below)
  * - `height`: Number of pixels high (EXIF orientation is not taken into consideration, see example below)

src/binding.gyp

@@ -21,6 +21,7 @@
         'defines': [
           '_VIPS_PUBLIC=__declspec(dllexport)',
           '_ALLOW_KEYWORD_MACROS',
+          '_HAS_EXCEPTIONS=1',
           'G_DISABLE_ASSERT',
           'G_DISABLE_CAST_CHECKS',
           'G_DISABLE_CHECKS'
@@ -148,7 +149,8 @@
           ['OS == "win"', {
             'defines': [
               '_ALLOW_KEYWORD_MACROS',
-              '_FILE_OFFSET_BITS=64'
+              '_FILE_OFFSET_BITS=64',
+              '_HAS_EXCEPTIONS=1'
             ],
             'link_settings': {
               'libraries': [

src/metadata.cc

@@ -151,13 +151,52 @@ class MetadataWorker : public Napi::AsyncWorker {
       }
       // PNG comments
       vips_image_map(image.get_image(), readPNGComment, &baton->comments);
+      // Media type
+      std::string mediaType;
+      switch (imageType) {
+        case sharp::ImageType::JPEG:
+        case sharp::ImageType::PNG:
+        case sharp::ImageType::WEBP:
+        case sharp::ImageType::JP2:
+        case sharp::ImageType::TIFF:
+        case sharp::ImageType::GIF:
+        case sharp::ImageType::FITS:
+        case sharp::ImageType::JXL:
+          baton->mediaType = "image/" + baton->format;
+          break;
+        case sharp::ImageType::SVG:
+          baton->mediaType = "image/svg+xml";
+          break;
+        case sharp::ImageType::HEIF:
+          if (baton->compression == "av1") {
+            baton->mediaType = "image/avif";
+          } else if (baton->compression == "hevc") {
+            baton->mediaType = "image/heic";
+          }
+          break;
+        case sharp::ImageType::PDF:
+          baton->mediaType = "application/pdf";
+          break;
+        case sharp::ImageType::OPENSLIDE:
+          baton->mediaType = "image/tiff";
+          break;
+        case sharp::ImageType::PPM:
+          baton->mediaType = "image/x-portable-pixmap";
+          break;
+        case sharp::ImageType::EXR:
+          baton->mediaType = "image/x-exr";
+          break;
+        case sharp::ImageType::RAD:
+          baton->mediaType = "image/vnd.radiance";
+          break;
+        case sharp::ImageType::UHDR:
+          baton->mediaType = "image/jpeg";
+          break;
+        default:
+          break;
+      }
     }
-    // Handle warnings
-    std::string warning = sharp::VipsWarningPop();
-    while (!warning.empty()) {
-      baton->warnings.push_back(warning);
-      warning = sharp::VipsWarningPop();
-    }
+
     // Clean up
     vips_error_clear();
     vips_thread_shutdown();
@@ -167,12 +206,19 @@ class MetadataWorker : public Napi::AsyncWorker {
     Napi::Env env = Env();
     Napi::HandleScope scope(env);
 
-    for (auto& warning : baton->warnings) {
+    // Handle warnings
+    std::string warning = sharp::VipsWarningPop();
+    while (!warning.empty()) {
       debuglog.Call(Receiver().Value(), { Napi::String::New(env, warning) });
+      warning = sharp::VipsWarningPop();
     }
+
     if (baton->err.empty()) {
       Napi::Object info = Napi::Object::New(env);
       info.Set("format", baton->format);
+      if (!baton->mediaType.empty()) {
+        info.Set("mediaType", baton->mediaType);
+      }
       if (baton->input->bufferLength > 0) {
         info.Set("size", baton->input->bufferLength);
       }

src/metadata.h

@@ -19,6 +19,7 @@ struct MetadataBaton {
   sharp::InputDescriptor *input;
   // Output
   std::string format;
+  std::string mediaType;
   int width;
   int height;
   std::string space;
@@ -57,7 +58,6 @@ struct MetadataBaton {
   size_t gainMapLength;
   MetadataComments comments;
   std::string err;
-  std::vector<std::string> warnings;
 
   MetadataBaton():
     input(nullptr),

src/pipeline.cc

@@ -1280,21 +1280,12 @@ class PipelineWorker : public Napi::AsyncWorker {
       } else {
         if (baton->input->failOn == VIPS_FAIL_ON_WARNING) {
           (baton->err).append("Warning treated as error due to failOn setting");
+          baton->errUseWarning = true;
         } else {
           (baton->err).append("Unknown error");
         }
       }
     }
-    // Handle warnings
-    std::string warning = sharp::VipsWarningPop();
-    while (!warning.empty()) {
-      if (baton->input->failOn == VIPS_FAIL_ON_WARNING) {
-        (baton->err).append("\n").append(warning);
-      } else {
-        (baton->warnings).push_back(warning);
-      }
-      warning = sharp::VipsWarningPop();
-    }
     // Clean up libvips' per-request data and threads
     vips_error_clear();
     vips_thread_shutdown();
@@ -1304,8 +1295,15 @@ class PipelineWorker : public Napi::AsyncWorker {
     Napi::Env env = Env();
     Napi::HandleScope scope(env);
 
-    for (auto &warning : baton->warnings) {
-      debuglog.Call(Receiver().Value(), { Napi::String::New(env, warning) });
+    // Handle warnings
+    std::string warning = sharp::VipsWarningPop();
+    while (!warning.empty()) {
+      if (baton->errUseWarning) {
+        (baton->err).append("\n").append(warning);
+      } else {
+        debuglog.Call(Receiver().Value(), { Napi::String::New(env, warning) });
+      }
+      warning = sharp::VipsWarningPop();
     }
     if (baton->err.empty()) {
       int width = baton->width;

src/pipeline.h

@@ -204,7 +204,6 @@ struct PipelineBaton {
   bool jxlLossless;
   VipsBandFormat rawDepth;
   std::string err;
-  std::vector<std::string> warnings;
   bool errUseWarning;
   int keepMetadata;
   int withMetadataOrientation;

src/stats.cc

@@ -96,12 +96,7 @@ class StatsWorker : public Napi::AsyncWorker {
         (baton->err).append(err.what());
       }
     }
-    // Handle warnings
-    std::string warning = sharp::VipsWarningPop();
-    while (!warning.empty()) {
-      baton->warnings.push_back(warning);
-      warning = sharp::VipsWarningPop();
-    }
+
     // Clean up
     vips_error_clear();
     vips_thread_shutdown();
@@ -111,8 +106,11 @@ class StatsWorker : public Napi::AsyncWorker {
     Napi::Env env = Env();
     Napi::HandleScope scope(env);
 
-    for (auto& warning : baton->warnings) {
+    // Handle warnings
+    std::string warning = sharp::VipsWarningPop();
+    while (!warning.empty()) {
       debuglog.Call(Receiver().Value(), { Napi::String::New(env, warning) });
+      warning = sharp::VipsWarningPop();
     }
     if (baton->err.empty()) {
       // Stats Object

src/stats.h

@@ -45,7 +45,6 @@ struct StatsBaton {
   int dominantBlue;
 
   std::string err;
-  std::vector<std::string> warnings;
 
   StatsBaton():
     input(nullptr),

test/unit/avif.js

@@ -36,6 +36,7 @@ describe('AVIF', () => {
       density: 72,
       depth: 'uchar',
       format: 'jpeg',
+      mediaType: 'image/jpeg',
       hasAlpha: false,
       hasProfile: false,
       // 32 / (2048 / 858) = 13.40625
@@ -64,6 +65,7 @@ describe('AVIF', () => {
       compression: 'av1',
       depth: 'uchar',
       format: 'heif',
+      mediaType: 'image/avif',
       hasAlpha: false,
       hasProfile: false,
       height: 26,
@@ -93,6 +95,7 @@ describe('AVIF', () => {
       compression: 'av1',
       depth: 'uchar',
       format: 'heif',
+      mediaType: 'image/avif',
       hasAlpha: false,
       hasProfile: false,
       height: 24,
@@ -119,6 +122,7 @@ describe('AVIF', () => {
       compression: 'av1',
       depth: 'uchar',
       format: 'heif',
+      mediaType: 'image/avif',
       hasAlpha: false,
       hasProfile: false,
       height: 13,
@@ -148,6 +152,7 @@ describe('AVIF', () => {
       compression: 'av1',
       depth: 'uchar',
       format: 'heif',
+      mediaType: 'image/avif',
       hasAlpha: true,
       hasProfile: false,
       height: 300,
@@ -178,6 +183,7 @@ describe('AVIF', () => {
       compression: 'av1',
       depth: 'uchar',
       format: 'heif',
+      mediaType: 'image/avif',
       hasAlpha: false,
       hasProfile: false,
       height: 26,
@@ -236,6 +242,7 @@ describe('AVIF', () => {
     void exif;
     assert.deepStrictEqual(metadata, {
       format: 'heif',
+      mediaType: 'image/avif',
       width: 4096,
       height: 800,
       space: 'srgb',
@@ -259,6 +266,7 @@ describe('AVIF', () => {
     const { size, ...pngMetadata } = await sharp(data).metadata();
     assert.deepStrictEqual(pngMetadata, {
       format: 'png',
+      mediaType: 'image/png',
       width: 4096,
       height: 800,
       space: 'srgb',

test/unit/metadata.js

@@ -19,6 +19,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputJpg).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('image/jpeg', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
@@ -41,6 +42,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputJpgWithExif).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('image/jpeg', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(450, metadata.width);
       assert.strictEqual(600, metadata.height);
@@ -66,6 +68,7 @@ describe('Image metadata', () => {
       const profile = icc.parse(metadata.icc);
       assert.strictEqual('object', typeof profile);
       assert.strictEqual('Generic RGB Profile', profile.description);
+      assert.strictEqual('image/jpeg', metadata.mediaType);
       done();
     });
   });
@@ -92,6 +95,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputTiff).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('tiff', metadata.format);
+      assert.strictEqual('image/tiff', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2464, metadata.width);
       assert.strictEqual(3248, metadata.height);
@@ -111,6 +115,7 @@ describe('Image metadata', () => {
       assert.strictEqual('undefined', typeof metadata.xmp);
       assert.strictEqual('undefined', typeof metadata.xmpAsString);
       assert.strictEqual('inch', metadata.resolutionUnit);
+      assert.strictEqual('image/tiff', metadata.mediaType);
       done();
     });
   });
@@ -119,6 +124,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputTiffMultipage).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('tiff', metadata.format);
+      assert.strictEqual('image/tiff', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2464, metadata.width);
       assert.strictEqual(3248, metadata.height);
@@ -142,6 +148,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputPng).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('png', metadata.format);
+      assert.strictEqual('image/png', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2809, metadata.width);
       assert.strictEqual(2074, metadata.height);
@@ -166,6 +173,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputPngTestJoinChannel).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('png', metadata.format);
+      assert.strictEqual('image/png', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(320, metadata.width);
       assert.strictEqual(240, metadata.height);
@@ -191,6 +199,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputPngWithTransparency).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('png', metadata.format);
+      assert.strictEqual('image/png', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2048, metadata.width);
       assert.strictEqual(1536, metadata.height);
@@ -225,6 +234,7 @@ describe('Image metadata', () => {
       height: 32,
       isPalette: false,
       isProgressive: false,
+      mediaType: 'image/png',
       space: 'b-w',
       width: 32,
       autoOrient: {
@@ -250,6 +260,7 @@ describe('Image metadata', () => {
       height: 32,
       isPalette: false,
       isProgressive: false,
+      mediaType: 'image/png',
       space: 'grey16',
       width: 32,
       autoOrient: {
@@ -263,6 +274,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputWebP).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('webp', metadata.format);
+      assert.strictEqual('image/webp', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(1024, metadata.width);
       assert.strictEqual(772, metadata.height);
@@ -285,11 +297,12 @@ describe('Image metadata', () => {
     sharp(fixtures.inputWebPAnimated)
       .metadata()
       .then(({
-        format, width, height, space, channels, depth,
+        format, mediaType, width, height, space, channels, depth,
         isProgressive, pages, loop, delay, hasProfile,
         hasAlpha
       }) => {
         assert.strictEqual(format, 'webp');
+        assert.strictEqual(mediaType, 'image/webp');
         assert.strictEqual(width, 80);
         assert.strictEqual(height, 80);
         assert.strictEqual(space, 'srgb');
@@ -308,11 +321,12 @@ describe('Image metadata', () => {
     sharp(fixtures.inputWebPAnimated, { pages: -1 })
       .metadata()
       .then(({
-        format, width, height, space, channels, depth,
+        format, mediaType, width, height, space, channels, depth,
         isProgressive, pages, pageHeight, loop, delay,
         hasProfile, hasAlpha
       }) => {
         assert.strictEqual(format, 'webp');
+        assert.strictEqual(mediaType, 'image/webp');
         assert.strictEqual(width, 80);
         assert.strictEqual(height, 720);
         assert.strictEqual(space, 'srgb');
@@ -332,11 +346,12 @@ describe('Image metadata', () => {
     sharp(fixtures.inputWebPAnimatedLoop3)
       .metadata()
       .then(({
-        format, width, height, space, channels, depth,
+        format, mediaType, width, height, space, channels, depth,
         isProgressive, pages, loop, delay, hasProfile,
         hasAlpha
       }) => {
         assert.strictEqual(format, 'webp');
+        assert.strictEqual(mediaType, 'image/webp');
         assert.strictEqual(width, 370);
         assert.strictEqual(height, 285);
         assert.strictEqual(space, 'srgb');
@@ -355,6 +370,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputGif).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('gif', metadata.format);
+      assert.strictEqual('image/gif', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(800, metadata.width);
       assert.strictEqual(533, metadata.height);
@@ -375,6 +391,7 @@ describe('Image metadata', () => {
     sharp(fixtures.inputGifGreyPlusAlpha).metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('gif', metadata.format);
+      assert.strictEqual('image/gif', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2, metadata.width);
       assert.strictEqual(1, metadata.height);
@@ -395,11 +412,12 @@ describe('Image metadata', () => {
     sharp(fixtures.inputGifAnimated)
       .metadata()
       .then(({
-        format, width, height, space, channels, depth,
+        format, mediaType, width, height, space, channels, depth,
         isProgressive, pages, loop, delay, background,
         hasProfile, hasAlpha
       }) => {
         assert.strictEqual(format, 'gif');
+        assert.strictEqual(mediaType, 'image/gif');
         assert.strictEqual(width, 80);
         assert.strictEqual(height, 80);
         assert.strictEqual(space, 'srgb');
@@ -419,11 +437,12 @@ describe('Image metadata', () => {
     sharp(fixtures.inputGifAnimatedLoop3)
       .metadata()
       .then(({
-        format, width, height, space, channels, depth,
+        format, mediaType, width, height, space, channels, depth,
         isProgressive, pages, loop, delay, hasProfile,
         hasAlpha
       }) => {
         assert.strictEqual(format, 'gif');
+        assert.strictEqual(mediaType, 'image/gif');
         assert.strictEqual(width, 370);
         assert.strictEqual(height, 285);
         assert.strictEqual(space, 'srgb');
@@ -462,6 +481,7 @@ describe('Image metadata', () => {
   it('File in, Promise out', (_t, done) => {
     sharp(fixtures.inputJpg).metadata().then((metadata) => {
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('image/jpeg', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
@@ -508,6 +528,7 @@ describe('Image metadata', () => {
     const pipeline = sharp();
     pipeline.metadata().then((metadata) => {
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('image/jpeg', metadata.mediaType);
       assert.strictEqual(829183, metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
@@ -559,6 +580,7 @@ describe('Image metadata', () => {
     const pipeline = sharp().metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('image/jpeg', metadata.mediaType);
       assert.strictEqual(829183, metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
@@ -583,6 +605,7 @@ describe('Image metadata', () => {
     image.metadata((err, metadata) => {
       if (err) throw err;
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('image/jpeg', metadata.mediaType);
       assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
@@ -642,7 +665,7 @@ describe('Image metadata', () => {
   });
 
   it('keep existing ICC profile', async () => {
-    const data = await sharp(fixtures.inputJpgWithExif, { failOn: 'error' })
+    const data = await sharp(fixtures.inputJpgWithExif)
       .keepIccProfile()
       .toBuffer();
 
@@ -675,7 +698,7 @@ describe('Image metadata', () => {
   });
 
   it('keep existing ICC profile, avoid colour transform', async () => {
-    const [r, g, b] = await sharp(fixtures.inputPngWithProPhotoProfile, { failOn: 'error' })
+    const [r, g, b] = await sharp(fixtures.inputPngWithProPhotoProfile)
       .keepIccProfile()
       .raw()
       .toBuffer();
@@ -721,7 +744,7 @@ describe('Image metadata', () => {
   });
 
   it('transform to invalid ICC profile emits warning', async () => {
-    const img = sharp({ create, failOn: 'error' })
+    const img = sharp({ create })
       .png()
       .withIccProfile(fixtures.path('invalid-illuminant.icc'));
 
@@ -917,6 +940,7 @@ describe('Image metadata', () => {
       .metadata()
       .then(metadata => {
         assert.strictEqual(metadata.format, 'tiff');
+        assert.strictEqual(metadata.mediaType, 'image/tiff');
         assert.strictEqual(metadata.width, 317);
         assert.strictEqual(metadata.height, 211);
         assert.strictEqual(metadata.space, 'rgb16');
@@ -931,6 +955,7 @@ describe('Image metadata', () => {
     const metadata = await sharp(fixtures.inputAvif).metadata();
     assert.deepStrictEqual(metadata, {
       format: 'heif',
+      mediaType: 'image/avif',
       width: 2048,
       height: 858,
       space: 'srgb',
@@ -1014,6 +1039,7 @@ describe('Image metadata', () => {
     const metadata = await sharp(fixtures.inputJpgLossless).metadata();
     assert.deepStrictEqual(metadata, {
       format: 'jpeg',
+      mediaType: 'image/jpeg',
       width: 227,
       height: 149,
       space: 'srgb',

test/unit/png.js

@@ -145,6 +145,7 @@ describe('PNG', () => {
         width: 68
       },
       format: 'png',
+      mediaType: 'image/png',
       width: 68,
       height: 68,
       space: 'srgb',