net: Move data reading functionalities from UploadElement to UploadElementReader

net/base/upload_element_reader.h

+// Copyright (c) 2012 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.
+
+#ifndef NET_BASE_UPLOAD_ELEMENT_READER_H_
+#define NET_BASE_UPLOAD_ELEMENT_READER_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/file_path.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time.h"
+#include "net/base/net_export.h"
+
+namespace net {
+
+class FileStream;
+class UploadElement;
+
+// An interface to read an upload data element.
+class NET_EXPORT UploadElementReader {
+ public:
+  UploadElementReader() {}
+  virtual ~UploadElementReader() {}
+
+  // Creates an appropriate UploadElementReader instance for the given element.
+  static UploadElementReader* Create(const UploadElement& element);
+
+  // Initializes the instance synchronously.
+  virtual int InitSync() = 0;
+
+  // Returns the byte-length of the element.  For files that do not exist, 0
+  // is returned.  This is done for consistency with Mozilla.
+  virtual uint64 GetContentLength() const = 0;
+
+  // Returns the number of bytes remaining to read.
+  virtual uint64 BytesRemaining() const = 0;
+
+  // Returns true if the upload element is entirely in memory.
+  // The default implementation returns false.
+  virtual bool IsInMemory() const;
+
+  // Reads up to |buf_length| bytes synchronously. Returns the number of bytes
+  // read. This function never fails. If there's less data to read than we
+  // initially observed, then pad with zero (this can happen with files).
+  // |buf_length| must be greater than 0.
+  virtual int ReadSync(char* buf, int buf_length) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(UploadElementReader);
+};
+
+// An UploadElementReader implementation for bytes.
+class NET_EXPORT UploadBytesElementReader : public UploadElementReader {
+ public:
+  UploadBytesElementReader(const char* bytes, int bytes_length);
+  virtual ~UploadBytesElementReader();
+
+  // UploadElementReader overrides:
+  virtual int InitSync() OVERRIDE;
+  virtual uint64 GetContentLength() const OVERRIDE;
+  virtual uint64 BytesRemaining() const OVERRIDE;
+  virtual int ReadSync(char* buf, int buf_length) OVERRIDE;
+  virtual bool IsInMemory() const OVERRIDE;
+
+ private:
+  const char* bytes_;
+  int bytes_length_;
+  int offset_;
+
+  DISALLOW_COPY_AND_ASSIGN(UploadBytesElementReader);
+};
+
+// An UploadElementReader implementation for file.
+class NET_EXPORT UploadFileElementReader : public UploadElementReader {
+ public:
+  UploadFileElementReader(const FilePath& path,
+                          uint64 range_offset,
+                          uint64 range_length,
+                          const base::Time& expected_modification_time);
+  virtual ~UploadFileElementReader();
+
+  // UploadElementReader overrides:
+  virtual int InitSync() OVERRIDE;
+  virtual uint64 GetContentLength() const OVERRIDE;
+  virtual uint64 BytesRemaining() const OVERRIDE;
+  virtual int ReadSync(char* buf, int buf_length) OVERRIDE;
+
+ private:
+  FilePath path_;
+  uint64 range_offset_;
+  uint64 range_length_;
+  base::Time expected_modification_time_;
+  scoped_ptr<FileStream> file_stream_;
+  uint64 content_length_;
+  uint64 bytes_remaining_;
+
+  // Sets an value to override the result for GetContentLength().
+  // Used for tests.
+  struct NET_EXPORT ScopedOverridingContentLengthForTests {
+    ScopedOverridingContentLengthForTests(uint64 value);
+    ~ScopedOverridingContentLengthForTests();
+  };
+
+  FRIEND_TEST_ALL_PREFIXES(UploadDataStreamTest, FileSmallerThanLength);
+  FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionTest,
+                           UploadFileSmallerThanLength);
+  FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionSpdy2Test,
+                           UploadFileSmallerThanLength);
+  FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionSpdy3Test,
+                           UploadFileSmallerThanLength);
+
+  DISALLOW_COPY_AND_ASSIGN(UploadFileElementReader);
+};
+
+}  // namespace net
+
+#endif  // NET_BASE_UPLOAD_ELEMENT_READER_H_