Initial commit of libimage_io

Image_io is a library for manipulating image files, especially XMP
metadata within them.

Test: m libimage_io
Bug: 109735087
Bug: 119211681
Change-Id: I657f307be0459fe40154806c7cd388b97bcb0ea5

1 files changed, 30 insertions, 0 deletions

diff --git a/includes/image_io/base/data_segment_data_source.h b/includes/image_io/base/data_segment_data_source.h
new file mode 100644
index 0000000..6ef6c3e
--- /dev/null
+++ b/includes/image_io/base/data_segment_data_source.h
@@ -0,0 +1,30 @@
+#ifndef IMAGE_IO_BASE_DATA_SEGMENT_DATA_SOURCE_H_  // NOLINT
+#define IMAGE_IO_BASE_DATA_SEGMENT_DATA_SOURCE_H_  // NOLINT
+
+#include "image_io/base/data_source.h"
+
+namespace photos_editing_formats {
+namespace image_io {
+
+/// DataSegmentDataSource is an implementation of DataSource that provides
+/// access to requested DataSegment instances from a single (possibly large)
+/// in-memory DataSegment.
+class DataSegmentDataSource : public DataSource {
+ public:
+  explicit DataSegmentDataSource(
+      const std::shared_ptr<DataSegment>& shared_data_segment)
+      : shared_data_segment_(shared_data_segment) {}
+  void Reset() override;
+  std::shared_ptr<DataSegment> GetDataSegment(size_t begin,
+                                              size_t min_size) override;
+  TransferDataResult TransferData(const DataRange& data_range, size_t best_size,
+                                  DataDestination* data_destination) override;
+
+ private:
+  std::shared_ptr<DataSegment> shared_data_segment_;
+};
+
+}  // namespace image_io
+}  // namespace photos_editing_formats
+
+#endif // IMAGE_IO_BASE_DATA_SEGMENT_DATA_SOURCE_H_  // NOLINT