Verify that all slice are downloaded when a stream complete

content/browser/download/download_file_impl.cc

Index: content/browser/download/download_file_impl.cc
diff --git a/content/browser/download/download_file_impl.cc b/content/browser/download/download_file_impl.cc
index 8b2a9e8e81585fb36be77bd083558ba356fc8ffa..90f59448e6369337feb9a2be525587a778d3a3e2 100644
--- a/content/browser/download/download_file_impl.cc
+++ b/content/browser/download/download_file_impl.cc
@@ -19,6 +19,7 @@
 #include "content/browser/download/download_interrupt_reasons_impl.h"
 #include "content/browser/download/download_net_log_parameters.h"
 #include "content/browser/download/download_stats.h"
+#include "content/browser/download/parallel_download_utils.h"
 #include "content/public/browser/browser_thread.h"
 #include "crypto/secure_hash.h"
 #include "crypto/sha2.h"
@@ -367,18 +368,8 @@ void DownloadFileImpl::StreamActive(SourceStream* source_stream) {
     // Inform observers.
     SendUpdate();
 
-    // TODO(xingliu): Use slice info to determine if the file is fully
-    // downloaded.
-    bool all_stream_complete = true;
-    for (auto& stream : source_streams_) {
-      if (!stream.second->is_finished()) {
-        all_stream_complete = false;
-        break;
-      }
-    }
-
     // All the stream reader are completed, shut down file IO processing.
-    if (all_stream_complete) {
+    if (IsDownloadCompleted()) {
       RecordFileBandwidth(bytes_seen_, disk_writes_time_,
                           base::TimeTicks::Now() - download_start_);
       weak_factory_.InvalidateWeakPtrs();
@@ -433,6 +424,46 @@ void DownloadFileImpl::WillWriteToDisk(size_t data_len) {
   rate_estimator_.Increment(data_len);
 }
 
+bool DownloadFileImpl::IsDownloadCompleted() {
+  SourceStream* stream_for_last_slice = nullptr;
+  int64_t last_slice_offset = 0;

[David Trainor- moved to gerrit, 2017/03/09 17:23:10]

You need to set this inside the if block below right?  Or just use
steam_for_last_slice->offset()?

[qinmin, 2017/03/09 17:42:25]

Good catch. I was using
steam_for_last_slice = source_stream.begin()->second to initialize
stream_for_last_slice. But that's not correct since all the source_streams may
have written 0 bytes. So I introduced this variable, but forgot to update the
for loop to update this variable.
Fixed.

+  for (auto& stream : source_streams_) {
+    SourceStream* source_stream = stream.second.get();
+    if (source_stream->offset() >= last_slice_offset &&
+        source_stream->bytes_written() > 0) {
+      stream_for_last_slice = source_stream;
+    }
+    if (!source_stream->is_finished())
+      return false;
+  }
+
+  if (!is_sparse_file_)
+    return true;
+
+  // Verify that all the file slices have been downloaded.
+  std::vector<DownloadItem::ReceivedSlice> slices_to_download =
+      FindSlicesToDownload(received_slices_);
+  if (slices_to_download.size() > 1) {
+    // If there are 1 or more holes in the file, download is not finished.
+    // Some streams might not have been added to |source_streams_| yet.
+    return false;
+  } else if (stream_for_last_slice) {
+    DCHECK_EQ(slices_to_download[0].received_bytes,
+              DownloadSaveInfo::kLengthFullContent);
+    // The last stream should not have a length limit. If it has, it might
+    // not reach the end of the file.
+    if (stream_for_last_slice->length() !=
+        DownloadSaveInfo::kLengthFullContent) {
+      return false;
+    }
+    DCHECK_EQ(slices_to_download[0].offset,
+              stream_for_last_slice->offset() +
+                  stream_for_last_slice->bytes_written());
+  }
+
+  return true;
+}
+
 DownloadFileImpl::RenameParameters::RenameParameters(
     RenameOption option,
     const base::FilePath& new_path,