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diff --git a/chromium/net/http/partial_data.h b/chromium/net/http/partial_data.h
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+++ b/chromium/net/http/partial_data.h
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+// Copyright (c) 2011 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_HTTP_PARTIAL_DATA_H_
+#define NET_HTTP_PARTIAL_DATA_H_
+
+#include "base/basictypes.h"
+#include "net/base/completion_callback.h"
+#include "net/http/http_byte_range.h"
+#include "net/http/http_request_headers.h"
+
+namespace disk_cache {
+class Entry;
+}
+
+namespace net {
+
+class HttpResponseHeaders;
+class IOBuffer;
+
+// This class provides support for dealing with range requests and the
+// subsequent partial-content responses. We use sparse cache entries to store
+// these requests. This class is tightly integrated with HttpCache::Transaction
+// and it is intended to allow a cleaner implementation of that class.
+//
+// In order to fulfill range requests, we may have to perform a sequence of
+// reads from the cache, interleaved with reads from the network / writes to the
+// cache. This class basically keeps track of the data required to perform each
+// of those individual network / cache requests.
+class PartialData {
+ public:
+  PartialData();
+  ~PartialData();
+
+  // Performs initialization of the object by examining the request |headers|
+  // and verifying that we can process the requested range. Returns true if
+  // we can process the requested range, and false otherwise.
+  bool Init(const HttpRequestHeaders& headers);
+
+  // Sets the headers that we should use to make byte range requests. This is a
+  // subset of the request extra headers, with byte-range related headers
+  // removed.
+  void SetHeaders(const HttpRequestHeaders& headers);
+
+  // Restores the byte-range headers, by appending the byte range to the headers
+  // provided to SetHeaders().
+  void RestoreHeaders(HttpRequestHeaders* headers) const;
+
+  // Starts the checks to perform a cache validation. Returns 0 when there is no
+  // need to perform more operations because we reached the end of the request
+  // (so 0 bytes should be actually returned to the user), a positive number to
+  // indicate that PrepareCacheValidation should be called, or an appropriate
+  // error code. If this method returns ERR_IO_PENDING, the |callback| will be
+  // notified when the result is ready.
+  int ShouldValidateCache(disk_cache::Entry* entry,
+                          const CompletionCallback& callback);
+
+  // Builds the required |headers| to perform the proper cache validation for
+  // the next range to be fetched.
+  void PrepareCacheValidation(disk_cache::Entry* entry,
+                              HttpRequestHeaders* headers);
+
+  // Returns true if the current range is stored in the cache.
+  bool IsCurrentRangeCached() const;
+
+  // Returns true if the current range is the last one needed to fulfill the
+  // user's request.
+  bool IsLastRange() const;
+
+  // Extracts info from headers already stored in the cache. Returns false if
+  // there is any problem with the headers. |truncated| should be true if we
+  // have an incomplete 200 entry.
+  bool UpdateFromStoredHeaders(const HttpResponseHeaders* headers,
+                               disk_cache::Entry* entry, bool truncated);
+
+  // Sets the byte current range to start again at zero (for a truncated entry).
+  void SetRangeToStartDownload();
+
+  // Returns true if the requested range is valid given the stored data.
+  bool IsRequestedRangeOK();
+
+  // Returns true if the response headers match what we expect, false otherwise.
+  bool ResponseHeadersOK(const HttpResponseHeaders* headers);
+
+  // Fixes the response headers to include the right content length and range.
+  // |success| is the result of the whole request so if it's false, we'll change
+  // the result code to be 416.
+  void FixResponseHeaders(HttpResponseHeaders* headers, bool success);
+
+  // Fixes the content length that we want to store in the cache.
+  void FixContentLength(HttpResponseHeaders* headers);
+
+  // Reads up to |data_len| bytes from the cache and stores them in the provided
+  // buffer (|data|). Basically, this is just a wrapper around the API of the
+  // cache that provides the right arguments for the current range. When the IO
+  // operation completes, OnCacheReadCompleted() must be called with the result
+  // of the operation.
+  int CacheRead(disk_cache::Entry* entry, IOBuffer* data, int data_len,
+                const net::CompletionCallback& callback);
+
+  // Writes |data_len| bytes to cache. This is basically a wrapper around the
+  // API of the cache that provides the right arguments for the current range.
+  int CacheWrite(disk_cache::Entry* entry, IOBuffer* data, int data_len,
+                 const net::CompletionCallback& callback);
+
+  // This method should be called when CacheRead() finishes the read, to update
+  // the internal state about the current range.
+  void OnCacheReadCompleted(int result);
+
+  // This method should be called after receiving data from the network, to
+  // update the internal state about the current range.
+  void OnNetworkReadCompleted(int result);
+
+  bool initial_validation() const { return initial_validation_; }
+
+ private:
+  class Core;
+  // Returns the length to use when scanning the cache.
+  int GetNextRangeLen();
+
+  // Completion routine for our callback.
+  void GetAvailableRangeCompleted(int result, int64 start);
+
+  int64 current_range_start_;
+  int64 cached_start_;
+  int64 resource_size_;
+  int cached_min_len_;
+  HttpByteRange byte_range_;  // The range requested by the user.
+  // The clean set of extra headers (no ranges).
+  HttpRequestHeaders extra_headers_;
+  bool range_present_;  // True if next range entry is already stored.
+  bool final_range_;
+  bool sparse_entry_;
+  bool truncated_;  // We have an incomplete 200 stored.
+  bool initial_validation_;  // Only used for truncated entries.
+  Core* core_;
+  CompletionCallback callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(PartialData);
+};
+
+}  // namespace net
+
+#endif  // NET_HTTP_PARTIAL_DATA_H_