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, 80 insertions, 0 deletions

diff --git a/includes/image_io/base/message_store.h b/includes/image_io/base/message_store.h
new file mode 100644
index 0000000..1d492f1
--- /dev/null
+++ b/includes/image_io/base/message_store.h
@@ -0,0 +1,80 @@
+#ifndef IMAGE_IO_BASE_MESSAGE_STORE_H_  // NOLINT
+#define IMAGE_IO_BASE_MESSAGE_STORE_H_  // NOLINT
+
+#include <vector>
+#include "image_io/base/message.h"
+
+namespace photos_editing_formats {
+namespace image_io {
+
+/// An abstract base class for storing and reporting on Messages.
+class MessageStore {
+ public:
+  virtual ~MessageStore() = default;
+
+  /// Clears the messages maintained by the store.
+  virtual void ClearMessages() = 0;
+
+  // @message The message to add to the store.
+  virtual void AddMessage(const Message& message) = 0;
+
+  /// @return A vector of messages maintained by the store; this vector may be
+  ///     empty even if the AddMessage function was called, depending on the
+  ///     concrete subclass is implemented.
+  virtual std::vector<Message> GetMessages() const = 0;
+
+  /// @return Whether the store has error messages or not. This value is
+  ///     guarenteed to be accurate based on the latest calls to the
+  ///     ClearMessages and AddMessage functions.
+  virtual bool HasErrorMessages() const = 0;
+};
+
+/// A MessageStore that saves the messages in a vector. The implementation of
+/// this class is not thread safe.
+class VectorMessageStore : public MessageStore {
+ public:
+  void ClearMessages() override { messages_.clear(); }
+  void AddMessage(const Message& message) override {
+    messages_.push_back(message);
+  }
+  std::vector<Message> GetMessages() const override { return messages_; }
+  bool HasErrorMessages() const override {
+    for (const auto& message : messages_) {
+      if (message.GetType() != Message::kStatus) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+ private:
+  std::vector<Message> messages_;
+};
+
+/// A MessageStore that simply keeps track of whether error messages have been
+/// added or not, but does not store the messages themselves. The implementation
+/// of this class is should not cause any crashes if run in a multi-threaded
+/// environment, though there may be some cases where erroneous results are
+/// returned by the HasErrorMessages function.
+class ErrorFlagMessageStore : public MessageStore {
+ public:
+  ErrorFlagMessageStore() : has_error_(false) {}
+  void ClearMessages() override { has_error_ = false; }
+  void AddMessage(const Message& message) override {
+    if (message.GetType() != Message::kStatus) {
+      has_error_ = true;
+    }
+  }
+  std::vector<Message> GetMessages() const override {
+    return std::vector<Message>();
+  }
+  bool HasErrorMessages() const override { return has_error_; }
+
+ private:
+  bool has_error_;
+};
+
+}  // namespace image_io
+}  // namespace photos_editing_formats
+
+#endif // IMAGE_IO_BASE_MESSAGE_STORE_H_  // NOLINT