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#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_BLOB_BLOB_DATA_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_BLOB_BLOB_DATA_H_

// This file is required via serialized_blob.typemap and, transitively,
// encoded_form_data.typemap. To avoid build circularity issues, it should not
// transitively include anything that is generated from a mojom_blink target.
//
// This requires some gymnastics below, to explicitly forward-declare the
// required types without reference to the generator output headers.

#include <memory>
#include <optional>

#include "base/synchronization/lock.h"
#include "base/thread_annotations.h"
#include "mojo/public/cpp/bindings/pending_remote.h"
#include "mojo/public/cpp/bindings/struct_ptr.h"
#include "mojo/public/cpp/system/data_pipe.h"
#include "third_party/blink/public/mojom/blob/data_element.mojom-blink-forward.h"
#include "third_party/blink/public/mojom/blob/file_backed_blob_factory.mojom-blink-forward.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/forward.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
#include "third_party/blink/renderer/platform/wtf/thread_safe_ref_counted.h"

namespace base {
class Time;
}

namespace blink {
namespace mojom {
namespace blink {
class Blob;

class BlobReaderClient;

class BlobRegistry;

class DataElement;
using DataElementPtr = mojo::StructPtr<DataElement>;
}
}  // namespace mojom

class BlobBytesProvider;
class BlobDataHandle;

class PLATFORM_EXPORT RawData : public ThreadSafeRefCounted<RawData> {
 public:
  static scoped_refptr<RawData> Create() {
    return base::AdoptRef(new RawData());
  }

  const uint8_t* data() const { return data_.data(); }
  size_t size() const { return data_.size(); }

  // Iterators, so this type meets the requirements of
  // `std::ranges::contiguous_range`.
  auto begin() const { return data_.begin(); }
  auto end() const { return data_.end(); }

  Vector<uint8_t>& MutableData() { return data_; }

 private:
  RawData();

  Vector<uint8_t> data_;
};

class PLATFORM_EXPORT BlobData {
  USING_FAST_MALLOC(BlobData);

 public:
  static constexpr int64_t kToEndOfFile = -1;
  enum class FileCompositionStatus {
    kSingleUnknownSizeFile,
    kNoUnknownSizeFiles
  };

  explicit BlobData(
      FileCompositionStatus = FileCompositionStatus::kNoUnknownSizeFiles);
  BlobData(const BlobData&) = delete;
  BlobData& operator=(const BlobData&) = delete;
  ~BlobData();

  const String& ContentType() const { return content_type_; }
  void SetContentType(const String&);

  const Vector<mojom::blink::DataElementPtr>& ElementsForTesting() const {
    return elements_;
  }
  Vector<mojom::blink::DataElementPtr> ReleaseElements();

  void AppendBytes(base::span<const uint8_t> bytes);
  void AppendData(scoped_refptr<RawData>);

  // The given blob must not be a file with unknown size. Please use the
  // File::appendTo instead.
  void AppendBlob(scoped_refptr<BlobDataHandle>,
                  int64_t offset,
                  int64_t length);
  void AppendText(const String&, bool normalize_line_endings_to_native);

  // The value of the size property for a Blob who has this data.
  // BlobDataItem::toEndOfFile if the Blob has a file whose size was not yet
  // determined.
  uint64_t length() const;

  bool IsSingleUnknownSizeFile() const {
    return file_composition_ == FileCompositionStatus::kSingleUnknownSizeFile;
  }

 private:
  void AppendDataInternal(base::span<const uint8_t> data,
                          scoped_refptr<RawData> = nullptr);

  String content_type_;
  FileCompositionStatus file_composition_;

  Vector<mojom::blink::DataElementPtr> elements_;
  size_t current_memory_population_ = 0;

  // These two members are used to combine multiple consecutive 'bytes' elements
  // (as created by `AppendBytes`, `AppendData` or `AppendText`) into a single
  // element. When one has a value the other also has a value. Before using
  // `elements_` to actually create a blob, `last_bytes_provider_` should be
  // bound to `last_bytes_provider_receiver_`.
  std::unique_ptr<BlobBytesProvider> last_bytes_provider_;
  mojo::PendingReceiver<mojom::blink::BytesProvider>
      last_bytes_provider_receiver_;
};

class PLATFORM_EXPORT BlobDataHandle
    : public ThreadSafeRefCounted<BlobDataHandle> {
  USING_FAST_MALLOC(BlobDataHandle);

 public:
  // For empty blob construction.
  static scoped_refptr<BlobDataHandle> Create() {
    return base::AdoptRef(new BlobDataHandle());
  }
  static scoped_refptr<BlobDataHandle> CreateForFile(
      mojom::blink::FileBackedBlobFactory* file_backed_blob_factory,
      const String& path,
      int64_t offset,
      int64_t length,
      const std::optional<base::Time>& expected_modification_time,
      const String& content_type);
  static scoped_refptr<BlobDataHandle> CreateForFileSync(
      mojom::blink::FileBackedBlobFactory* file_backed_blob_factory,
      const String& path,
      int64_t offset,
      int64_t length,
      const std::optional<base::Time>& expected_modification_time,
      const String& content_type);

  // For initial creation.
  static scoped_refptr<BlobDataHandle> Create(std::unique_ptr<BlobData> data,
                                              uint64_t size) {
    return base::AdoptRef(new BlobDataHandle(std::move(data), size));
  }

  static scoped_refptr<BlobDataHandle> CreateForTesting(const String& uuid,
                                                        const String& type,
                                                        uint64_t size) {
    return base::AdoptRef(new BlobDataHandle(uuid, type, size));
  }

  static scoped_refptr<BlobDataHandle> Create(
      const String& uuid,
      const String& type,
      uint64_t size,
      mojo::PendingRemote<mojom::blink::Blob>);

  String Uuid() const { return uuid_; }
  String GetType() const { return type_; }
  uint64_t size() const { return size_; }

  bool IsSingleUnknownSizeFile() const { return is_single_unknown_size_file_; }

  ~BlobDataHandle();

  mojo::PendingRemote<mojom::blink::Blob> CloneBlobRemote();
  void CloneBlobRemote(mojo::PendingReceiver<mojom::blink::Blob>);

  void ReadAll(mojo::ScopedDataPipeProducerHandle,
               mojo::PendingRemote<mojom::blink::BlobReaderClient>);

  // This does synchronous IPC, and possibly synchronous file operations. Think
  // twice before calling this function.
  bool CaptureSnapshot(uint64_t* snapshot_size,
                       std::optional<base::Time>* snapshot_modification_time);

  void SetBlobRemoteForTesting(mojo::PendingRemote<mojom::blink::Blob> remote) {
    base::AutoLock locker(blob_remote_lock_);
    blob_remote_ = std::move(remote);
  }

  static mojom::blink::BlobRegistry* GetBlobRegistry();
  static void SetBlobRegistryForTesting(mojom::blink::BlobRegistry*);

 private:
  BlobDataHandle();
  BlobDataHandle(std::unique_ptr<BlobData>, uint64_t size);
  BlobDataHandle(mojom::blink::FileBackedBlobFactory* file_backed_blob_factory,
                 mojom::blink::DataElementFilePtr file_element,
                 const String& content_type,
                 uint64_t size,
                 bool synchronous_register = false);
  BlobDataHandle(const String& uuid, const String& type, uint64_t size);
  BlobDataHandle(const String& uuid,
                 const String& type,
                 uint64_t size,
                 mojo::PendingRemote<mojom::blink::Blob>);

  // This UUID is deprecated and should not be used to reference the blob in the
  // backend (BlobRegistry). TODO(crbug.com/40529364): remove.
  const String uuid_;
  const String type_;
  const uint64_t size_;
  const bool is_single_unknown_size_file_;
  // This class is supposed to be thread safe. So to be able to use the mojo
  // Blob interface from multiple threads store a PendingRemote combined with
  // a lock, and make sure any access to the mojo interface is done protected
  // by the lock.
  mojo::PendingRemote<mojom::blink::Blob> blob_remote_
      GUARDED_BY(blob_remote_lock_);
  base::Lock blob_remote_lock_;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_BLOB_BLOB_DATA_H_