Revert of Media Galleries Partial Deprecation: Remove image metadata & libexif.

chrome/utility/media_galleries/image_metadata_extractor.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/utility/media_galleries/image_metadata_extractor.h"
+
+extern "C" {
+#include <libexif/exif-data.h>
+#include <libexif/exif-loader.h>
+}  // extern "C"
+#include <stddef.h>
+#include <stdint.h>
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/files/file_path.h"
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/numerics/safe_conversions.h"
+#include "base/path_service.h"
+#include "base/scoped_native_library.h"
+#include "base/strings/string_number_conversions.h"
+#include "build/build_config.h"
+#include "content/public/common/content_paths.h"
+#include "media/base/data_source.h"
+#include "net/base/io_buffer.h"
+
+namespace metadata {
+
+namespace {
+
+const size_t kMaxBufferSize = 50 * 1024 * 1024;  // Arbitrary maximum of 50MB.
+
+typedef base::Callback<void(const scoped_refptr<net::DrainableIOBuffer>&)>
+    GotImageCallback;
+
+void FinishGetImageBytes(
+    const scoped_refptr<net::DrainableIOBuffer>& buffer,
+    media::DataSource* source,
+    const GotImageCallback& callback,
+    int bytes_read) {
+  if (bytes_read == media::DataSource::kReadError) {
+    callback.Run(NULL);
+    return;
+  }
+
+  buffer->DidConsume(bytes_read);
+  // Didn't get the whole file. Continue reading to get the rest.
+  if (buffer->BytesRemaining() > 0) {
+    source->Read(0, buffer->BytesRemaining(),
+                 reinterpret_cast<uint8_t*>(buffer->data()),
+                 base::Bind(&FinishGetImageBytes, buffer,
+                            base::Unretained(source), callback));
+    return;
+  }
+
+  buffer->SetOffset(0);
+  callback.Run(buffer);
+}
+
+void GetImageBytes(
+    media::DataSource* source,
+    const GotImageCallback& callback) {
+  int64_t size64 = 0;
+  if (!source->GetSize(&size64) ||
+      base::saturated_cast<size_t>(size64) > kMaxBufferSize) {
+    return callback.Run(NULL);
+  }
+  int size = base::checked_cast<int>(size64);
+
+  scoped_refptr<net::DrainableIOBuffer> buffer(
+      new net::DrainableIOBuffer(new net::IOBuffer(size), size));
+  source->Read(0, buffer->BytesRemaining(),
+               reinterpret_cast<uint8_t*>(buffer->data()),
+               base::Bind(&FinishGetImageBytes, buffer,
+                          base::Unretained(source), callback));
+}
+
+class ExifFunctions {
+ public:
+  ExifFunctions() : exif_loader_write_func_(NULL),
+                    exif_loader_new_func_(NULL),
+                    exif_loader_unref_func_(NULL),
+                    exif_loader_get_data_func_(NULL),
+                    exif_data_free_func_(NULL),
+                    exif_data_get_byte_order_func_(NULL),
+                    exif_get_short_func_(NULL),
+                    exif_get_long_func_(NULL),
+                    exif_get_rational_func_(NULL),
+                    exif_entry_get_value_func_(NULL),
+                    exif_content_get_entry_func_(NULL) {
+  }
+
+  bool Initialize(const base::FilePath& module_dir) {
+    if (exif_lib_.is_valid())
+      return true;
+
+#if defined(OS_WIN)
+    base::FilePath module_path = module_dir.AppendASCII("libexif.dll");
+#elif defined(OS_MACOSX)
+    base::FilePath module_path = module_dir.AppendASCII("exif.so");
+#elif defined(OS_CHROMEOS)
+    // On ChromeOS, we build and distribute our own version of libexif.
+    base::FilePath module_path = module_dir.AppendASCII("libexif.so");
+#else
+    // On Linux-like systems, we use the system libexif.
+    base::FilePath module_path = base::FilePath().AppendASCII("libexif.so.12");
+#endif
+
+    base::NativeLibraryLoadError error;
+    base::ScopedNativeLibrary lib(base::LoadNativeLibrary(module_path, &error));
+    if (!lib.is_valid()) {
+      LOG(ERROR) << "Couldn't load libexif. " << error.ToString();
+      return false;
+    }
+
+    if (!GetFunctionPointer(lib, &exif_loader_write_func_,
+                            "exif_loader_write") ||
+        !GetFunctionPointer(lib, &exif_loader_new_func_, "exif_loader_new") ||
+        !GetFunctionPointer(lib, &exif_loader_unref_func_,
+                            "exif_loader_unref") ||
+        !GetFunctionPointer(lib, &exif_loader_get_data_func_,
+                            "exif_loader_get_data") ||
+        !GetFunctionPointer(lib, &exif_data_free_func_, "exif_data_free") ||
+        !GetFunctionPointer(lib, &exif_data_get_byte_order_func_,
+                            "exif_data_get_byte_order") ||
+        !GetFunctionPointer(lib, &exif_get_short_func_, "exif_get_short") ||
+        !GetFunctionPointer(lib, &exif_get_long_func_, "exif_get_long") ||
+        !GetFunctionPointer(lib, &exif_get_rational_func_,
+                            "exif_get_rational") ||
+        !GetFunctionPointer(lib, &exif_entry_get_value_func_,
+                            "exif_entry_get_value") ||
+        !GetFunctionPointer(lib, &exif_content_get_entry_func_,
+                            "exif_content_get_entry")) {
+      return false;
+    }
+
+    exif_lib_.Reset(lib.Release());
+    return true;
+  }
+
+  ExifData* ParseExifFromBuffer(unsigned char* buffer, unsigned int size) {
+    DCHECK(exif_lib_.is_valid());
+    ExifLoader* loader = exif_loader_new_func_();
+    exif_loader_write_func_(loader, buffer, size);
+
+    ExifData* data = exif_loader_get_data_func_(loader);
+
+    exif_loader_unref_func_(loader);
+    loader = NULL;
+
+    return data;
+  }
+
+  void ExifDataFree(ExifData* data) {
+    DCHECK(exif_lib_.is_valid());
+    return exif_data_free_func_(data);
+  }
+
+  void ExtractInt(ExifData* data, ExifTag tag, int* result) {
+    DCHECK(exif_lib_.is_valid());
+    DCHECK(result);
+
+    ExifEntry* entry = ExifContentGetEntry(data, tag);
+    if (!entry)
+      return;
+
+    ExifByteOrder order = exif_data_get_byte_order_func_(data);
+    switch (entry->format) {
+      case EXIF_FORMAT_SHORT: {
+        ExifShort v = exif_get_short_func_(entry->data, order);
+        *result = base::checked_cast<int>(v);
+        break;
+      }
+      case EXIF_FORMAT_LONG: {
+        ExifLong v = exif_get_long_func_(entry->data, order);
+        // Ignore values that don't fit in a signed int - likely invalid data.
+        if (base::IsValueInRangeForNumericType<int>(v))
+          *result = base::checked_cast<int>(v);
+        break;
+      }
+      default: {
+        // Ignore all other entry formats.
+      }
+    }
+  }
+
+  void ExtractDouble(ExifData* data, ExifTag tag, double* result) {
+    DCHECK(exif_lib_.is_valid());
+    DCHECK(result);
+
+    ExifEntry* entry = ExifContentGetEntry(data, tag);
+    if (!entry)
+      return;
+
+    ExifByteOrder order = exif_data_get_byte_order_func_(data);
+
+    if (entry->format == EXIF_FORMAT_RATIONAL) {
+      ExifRational v = exif_get_rational_func_(entry->data, order);
+      *result = base::checked_cast<double>(v.numerator) /
+          base::checked_cast<double>(v.denominator);
+    }
+  }
+
+  void ExtractString(ExifData* data, ExifTag tag, std::string* result) {
+    DCHECK(exif_lib_.is_valid());
+    DCHECK(result);
+
+    ExifEntry* entry = ExifContentGetEntry(data, tag);
+    if (!entry)
+      return;
+
+    char buf[1024];
+    exif_entry_get_value_func_(entry, buf, sizeof(buf));
+    *result = buf;
+  }
+
+ private:
+  // Exported by libexif.
+  typedef unsigned char (*ExifLoaderWriteFunc)(ExifLoader* eld,
+                                               unsigned char* buf,
+                                               unsigned int len);
+  typedef ExifLoader* (*ExifLoaderNewFunc)();
+  typedef void (*ExifLoaderUnrefFunc)(ExifLoader* loader);
+  typedef ExifData* (*ExifLoaderGetDataFunc)(ExifLoader* loader);
+  typedef void (*ExifDataFreeFunc)(ExifData* data);
+  typedef ExifByteOrder (*ExifDataGetByteOrderFunc)(ExifData* data);
+  typedef ExifShort (*ExifGetShortFunc)(const unsigned char *buf,
+                                        ExifByteOrder order);
+  typedef ExifLong (*ExifGetLongFunc)(const unsigned char *buf,
+                                      ExifByteOrder order);
+  typedef ExifRational (*ExifGetRationalFunc)(const unsigned char *buf,
+                                              ExifByteOrder order);
+  typedef const char* (*ExifEntryGetValueFunc)(ExifEntry *e, char *val,
+                                               unsigned int maxlen);
+  typedef ExifEntry* (*ExifContentGetEntryFunc)(ExifContent* content,
+                                                ExifTag tag);
+
+  template<typename FunctionType>
+  bool GetFunctionPointer(const base::ScopedNativeLibrary& lib,
+                          FunctionType* function, const char* name) {
+    DCHECK(lib.is_valid());
+    DCHECK(function);
+    DCHECK(!(*function));
+    *function = reinterpret_cast<FunctionType>(
+        lib.GetFunctionPointer(name));
+    DLOG_IF(WARNING, !(*function)) << "Missing " << name;
+    return *function != NULL;
+  }
+
+  // Redefines exif_content_get_entry macro in terms of function pointer.
+  ExifEntry* ExifContentGetEntry(ExifData* data, ExifTag tag) {
+    DCHECK(exif_lib_.is_valid());
+    const ExifIfd ifds[] =
+        { EXIF_IFD_0, EXIF_IFD_1, EXIF_IFD_EXIF, EXIF_IFD_GPS };
+
+    for (size_t i = 0; i < arraysize(ifds); ++i) {
+      ExifEntry* entry = exif_content_get_entry_func_(data->ifd[ifds[i]], tag);
+      if (entry)
+        return entry;
+    }
+
+    return NULL;
+  }
+
+  ExifLoaderWriteFunc exif_loader_write_func_;
+  ExifLoaderNewFunc exif_loader_new_func_;
+  ExifLoaderUnrefFunc exif_loader_unref_func_;
+  ExifLoaderGetDataFunc exif_loader_get_data_func_;
+  ExifDataFreeFunc exif_data_free_func_;
+  ExifDataGetByteOrderFunc exif_data_get_byte_order_func_;
+  ExifGetShortFunc exif_get_short_func_;
+  ExifGetLongFunc exif_get_long_func_;
+  ExifGetRationalFunc exif_get_rational_func_;
+  ExifEntryGetValueFunc exif_entry_get_value_func_;
+  ExifContentGetEntryFunc exif_content_get_entry_func_;
+
+  base::ScopedNativeLibrary exif_lib_;
+  DISALLOW_COPY_AND_ASSIGN(ExifFunctions);
+};
+
+static base::LazyInstance<ExifFunctions> g_exif_lib = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+// static
+bool ImageMetadataExtractor::InitializeLibrary() {
+  base::FilePath media_path;
+  if (!PathService::Get(content::DIR_MEDIA_LIBS, &media_path))
+    return false;
+  return g_exif_lib.Get().Initialize(media_path);
+}
+
+// static
+bool ImageMetadataExtractor::InitializeLibraryForTesting() {
+  base::FilePath module_dir;
+  if (!PathService::Get(base::DIR_EXE, &module_dir))
+    return false;
+  return g_exif_lib.Get().Initialize(module_dir);
+}
+
+ImageMetadataExtractor::ImageMetadataExtractor()
+    : extracted_(false),
+      width_(-1),
+      height_(-1),
+      rotation_(-1),
+      x_resolution_(-1),
+      y_resolution_(-1),
+      exposure_time_sec_(-1),
+      flash_fired_(false),
+      f_number_(-1),
+      focal_length_mm_(-1),
+      iso_equivalent_(-1) {
+}
+
+ImageMetadataExtractor::~ImageMetadataExtractor() {
+}
+
+void ImageMetadataExtractor::Extract(media::DataSource* source,
+                                     const DoneCallback& callback) {
+  DCHECK(!extracted_);
+
+  GetImageBytes(source, base::Bind(&ImageMetadataExtractor::FinishExtraction,
+                                   base::Unretained(this), callback));
+}
+
+int ImageMetadataExtractor::width() const {
+  DCHECK(extracted_);
+  return width_;
+}
+
+int ImageMetadataExtractor::height() const {
+  DCHECK(extracted_);
+  return height_;
+}
+
+int ImageMetadataExtractor::rotation() const {
+  DCHECK(extracted_);
+  return rotation_;
+}
+
+double ImageMetadataExtractor::x_resolution() const {
+  DCHECK(extracted_);
+  return x_resolution_;
+}
+
+double ImageMetadataExtractor::y_resolution() const {
+  DCHECK(extracted_);
+  return y_resolution_;
+}
+
+const std::string& ImageMetadataExtractor::date() const {
+  DCHECK(extracted_);
+  return date_;
+}
+
+const std::string& ImageMetadataExtractor::camera_make() const {
+  DCHECK(extracted_);
+  return camera_make_;
+}
+
+const std::string& ImageMetadataExtractor::camera_model() const {
+  DCHECK(extracted_);
+  return camera_model_;
+}
+
+double ImageMetadataExtractor::exposure_time_sec() const {
+  DCHECK(extracted_);
+  return exposure_time_sec_;
+}
+
+bool ImageMetadataExtractor::flash_fired() const {
+  DCHECK(extracted_);
+  return flash_fired_;
+}
+
+double ImageMetadataExtractor::f_number() const {
+  DCHECK(extracted_);
+  return f_number_;
+}
+
+double ImageMetadataExtractor::focal_length_mm() const {
+  DCHECK(extracted_);
+  return focal_length_mm_;
+}
+
+int ImageMetadataExtractor::iso_equivalent() const {
+  DCHECK(extracted_);
+  return iso_equivalent_;
+}
+
+void ImageMetadataExtractor::FinishExtraction(
+    const DoneCallback& callback,
+    const scoped_refptr<net::DrainableIOBuffer>& buffer) {
+  if (!buffer.get()) {
+    callback.Run(false);
+    return;
+  }
+
+  ExifData* data = g_exif_lib.Get().ParseExifFromBuffer(
+      reinterpret_cast<unsigned char*>(buffer->data()),
+      buffer->BytesRemaining());
+
+  if (!data) {
+    callback.Run(false);
+    return;
+  }
+
+  g_exif_lib.Get().ExtractInt(data, EXIF_TAG_IMAGE_WIDTH, &width_);
+  g_exif_lib.Get().ExtractInt(data, EXIF_TAG_IMAGE_LENGTH, &height_);
+
+  // We ignore the mirrored-aspect of the mirrored-orientations and just
+  // indicate the rotation. Mirrored-orientations are very rare.
+  int orientation = 0;
+  g_exif_lib.Get().ExtractInt(data, EXIF_TAG_ORIENTATION, &orientation);
+  switch (orientation) {
+    case 1:
+    case 2:
+      rotation_ = 0;
+      break;
+    case 3:
+    case 4:
+      rotation_ = 180;
+      break;
+    case 5:
+    case 6:
+      rotation_ = 90;
+      break;
+    case 7:
+    case 8:
+      rotation_ = 270;
+      break;
+  }
+
+  g_exif_lib.Get().ExtractDouble(data, EXIF_TAG_X_RESOLUTION, &x_resolution_);
+  g_exif_lib.Get().ExtractDouble(data, EXIF_TAG_Y_RESOLUTION, &y_resolution_);
+
+  g_exif_lib.Get().ExtractString(data, EXIF_TAG_DATE_TIME, &date_);
+
+  g_exif_lib.Get().ExtractString(data, EXIF_TAG_MAKE, &camera_make_);
+  g_exif_lib.Get().ExtractString(data, EXIF_TAG_MODEL, &camera_model_);
+  g_exif_lib.Get().ExtractDouble(data, EXIF_TAG_EXPOSURE_TIME,
+                                 &exposure_time_sec_);
+
+  int flash_value = -1;
+  g_exif_lib.Get().ExtractInt(data, EXIF_TAG_FLASH, &flash_value);
+  if (flash_value >= 0) {
+    flash_fired_ = (flash_value & 0x1) != 0;
+  }
+
+  g_exif_lib.Get().ExtractDouble(data, EXIF_TAG_FNUMBER, &f_number_);
+  g_exif_lib.Get().ExtractDouble(data, EXIF_TAG_FOCAL_LENGTH,
+                                 &focal_length_mm_);
+  g_exif_lib.Get().ExtractInt(data, EXIF_TAG_ISO_SPEED_RATINGS,
+                              &iso_equivalent_);
+
+  g_exif_lib.Get().ExifDataFree(data);
+
+  extracted_ = true;
+
+  callback.Run(true);
+}
+
+}  // namespace metadata