Removed unnecessary map.

pdf/document_loader.cc

 // Copyright (c) 2010 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.
 
 #include "pdf/document_loader.h"
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "net/http/http_util.h"
 #include "ppapi/c/pp_errors.h"
@@ skipping 75 matching lines @@
   if (StartsWithASCII(disposition, "attachment", false)) {
     return false;
   }
 
   if (content_length > 0)
     chunk_stream_.Preallocate(content_length);
 
   document_size_ = content_length;
   requests_count_ = 0;
 
-  // Document loading strategy.
-  // Following table shows the growth on the minimal request size depending
-  // on the number requests that has been made already.
-  chunk_size_table_[10] = 32*1024;
-  chunk_size_table_[20] = 64*1024;
-  chunk_size_table_[30] = 128*1024;
-  chunk_size_table_[40] = 256*1024;
-  chunk_size_table_[50] = 512*1024;
-  chunk_size_table_[60] = 1024*1024;
-  chunk_size_table_[70] = 2048*1024;
-
   // Enable partial loading only if file size is above the threshold.
   // It will allow avoiding latency for multiple requests.
   if (content_length > kMinFileSize &&
       accept_ranges_bytes &&
       !content_encoded) {
     LoadPartialDocument();
   } else {
     LoadFullDocument();
   }
   return true;
@@ skipping 381 matching lines @@
     // Let's keep downloading PDF file in small chunks.
     uint32 pos = chunk_stream_.GetFirstMissingByte();
     std::vector<std::pair<size_t, size_t> > ranges;
     chunk_stream_.GetMissedRanges(pos, GetRequestSize(), &ranges);
     DCHECK(ranges.size() > 0);
     RequestData(ranges[0].first, ranges[0].second);
   }
 }
 
 uint32 DocumentLoader::GetRequestSize() const {
-  std::map<uint32, uint32>::const_iterator iter =
-      chunk_size_table_.lower_bound(requests_count_);
-  if (iter == chunk_size_table_.end())
-    iter--;
-  return iter->second;
+  // Document loading strategy:
+  // For first 10 requests, we use 32k chunk sizes, for the next 10 requests we
+  // double the size (64k), and so on, until we cap max request size at 2M for
+  // 71 or more requests.
+  uint32 limited_count = std::min(std::max(requests_count_, 10u), 70u);
+  return 32*1024 * (1 << ((limited_count - 1) / 10u));
 }
 
 }  // namespace chrome_pdf