Index: content/browser/download/base_file.h |
diff --git a/content/browser/download/base_file.h b/content/browser/download/base_file.h |
index 8351c49be340654f99fce3e0f41477ecb77f65a6..e630d778cfd88e68748c33574d124c7e260fcc7d 100644 |
--- a/content/browser/download/base_file.h |
+++ b/content/browser/download/base_file.h |
@@ -61,36 +61,52 @@ class CONTENT_EXPORT BaseFile { |
// will not attempt to determine the |full_path|. |
// |
// |bytes_so_far|: If a file is provided (via |full_path| or |file|), then |
- // this argument specifies the size of the file to expect. It is legal for |
- // the file to be larger, in which case the file will be truncated down to |
- // this size. However, if the file is shorter, then the operation will |
+ // this argument specifies the amount of data that has been written to |
+ // the file. If |is_sparse_file| is false, this value should be the size |
+ // of the file to expect. It is legal for the file to be larger, in which |
+ // case the file will be truncated down to this size if |is_sparse_file| |
+ // is false. However, if the file is shorter, then the operation will |
// fail with DOWNLOAD_INTERRUPT_REASON_FILE_TOO_SHORT. |
+ |
// |
- // |hash_so_far|: If |bytes_so_far| is non-zero, this specifies the SHA-256 |
- // hash of the first |bytes_so_far| bytes of the target file. If |
- // specified, BaseFile will read the first |bytes_so_far| of the target |
- // file in order to calculate the hash and verify that the file matches. |
- // If there's a mismatch, then the operation fails with |
- // DOWNLOAD_INTERRUPT_REASON_FILE_HASH_MISMATCH. Not used if |hash_state| |
- // is also specified. |
+ // |hash_so_far|: If |bytes_so_far| is non-zero and |is_sparse_file| is |
+ // false, this specifies the SHA-256 hash of the first |bytes_so_far| |
+ // bytes of the target file. If specified, BaseFile will read the first |
+ // |bytes_so_far| of the target file in order to calculate the hash and |
+ // verify that the file matches. If there's a mismatch, then the operation |
+ // fails with DOWNLOAD_INTERRUPT_REASON_FILE_HASH_MISMATCH. Not used if |
+ // |hash_state| is also specified. |
// |
// |hash_state|: The partial hash object to use. Only meaningful if there's a |
// preexisting target file and it is non-empty (i.e. bytes_so_far is |
// non-zero). If specified, BaseFile will assume that the bytes up to |
// |bytes_so_far| has been accurately hashed into |hash_state| and will |
- // ignore |hash_so_far|. |
+ // ignore |hash_so_far|. Not used if |is_sparse_file| is true. |
+ // |
+ // |is_sparse_file|: Specifies whether the file is a sparse file. If so, it is |
+ // possible that a write can happen at an offset that is larger than the |
+ // file size, thus creating holes in it. |
DownloadInterruptReason Initialize( |
const base::FilePath& full_path, |
const base::FilePath& default_directory, |
base::File file, |
int64_t bytes_so_far, |
const std::string& hash_so_far, |
- std::unique_ptr<crypto::SecureHash> hash_state); |
+ std::unique_ptr<crypto::SecureHash> hash_state, |
+ bool is_sparse_file); |
// Write a new chunk of data to the file. Returns a DownloadInterruptReason |
- // indicating the result of the operation. |
+ // indicating the result of the operation. Works only if |is_sparse_file| is |
+ // false. |
DownloadInterruptReason AppendDataToFile(const char* data, size_t data_len); |
+ // Write a new chunk of data to the file. Returns a DownloadInterruptReason |
+ // indicating the result of the operation. |
+ DownloadInterruptReason WriteDataToFile( |
+ int64_t offset, |
+ const char* data, |
+ size_t data_len); |
+ |
// Rename the download file. Returns a DownloadInterruptReason indicating the |
// result of the operation. A return code of NONE indicates that the rename |
// was successful. After a failure, the full_path() and in_progress() can be |
@@ -111,7 +127,8 @@ class CONTENT_EXPORT BaseFile { |
// Indicate that the download has finished. No new data will be received. |
// Returns the SecureHash object representing the state of the hash function |
- // at the end of the operation. |
+ // at the end of the operation. If |is_sparse_file_| is true, calling this |
+ // will cause |secure_hash_| to get calculated. |
std::unique_ptr<crypto::SecureHash> Finish(); |
// Informs the OS that this file came from the internet. Returns a |
@@ -137,7 +154,10 @@ class CONTENT_EXPORT BaseFile { |
// renamed. |
bool in_progress() const { return file_.IsValid(); } |
- // Returns the number of bytes in the file pointed to by full_path(). |
+ // Returns the number of bytes that has been written so far. If |
+ // |is_sparse_file_| is false, this should always be equal to the file size. |
+ // If |is_sparse_file_| is true, this should not be larger than the file size |
+ // as the file may contain holes in it. |
int64_t bytes_so_far() const { return bytes_so_far_; } |
std::string DebugString() const; |
@@ -148,13 +168,15 @@ class CONTENT_EXPORT BaseFile { |
// Creates and opens the file_ if it is invalid. |
// |
- // If |hash_so_far| is not empty, then it must match the SHA-256 hash of the |
- // first |bytes_so_far_| bytes of |file_|. If there's a hash mismatch, Open() |
- // fails with DOWNLOAD_INTERRUPT_REASON_FILE_HASH_MISMATCH. |
+ // If |is_sparse_file_| is false and |hash_so_far| is not empty, then it must |
+ // match the SHA-256 hash of the first |bytes_so_far_| bytes of |file_|. If |
+ // there's a hash mismatch, Open() fails with |
+ // DOWNLOAD_INTERRUPT_REASON_FILE_HASH_MISMATCH. |
// |
// If the opened file is shorter than |bytes_so_far_| bytes, then Open() fails |
- // with DOWNLOAD_INTERRUPT_REASON_FILE_TOO_SHORT. If the opened file is |
- // longer, then the file is truncated to |bytes_so_far_|. |
+ // with DOWNLOAD_INTERRUPT_REASON_FILE_TOO_SHORT. If the opened file is longer |
+ // and |is_sparse_file_| is false, then the file is truncated to |
+ // |bytes_so_far_|. |
// |
// Open() can fail for other reasons as well. In that case, it returns a |
// relevant interrupt reason. Unless Open() return |
@@ -185,6 +207,8 @@ class CONTENT_EXPORT BaseFile { |
// |
// If the result is REASON_NONE, then on return |secure_hash_| is valid and |
// is ready to hash bytes from offset |bytes_so_far_| + 1. |
+ // If |is_sparse_file_| is true, this function is only called when Finish() |
+ // is called. |
DownloadInterruptReason CalculatePartialHash( |
const std::string& hash_to_expect); |
@@ -222,6 +246,11 @@ class CONTENT_EXPORT BaseFile { |
// won't delete it on destruction. |
bool detached_ = false; |
+ // Whether the file is sparse. |
+ // TODO(qinmin): pass the slice information to this class so that we can |
+ // verify that writes are not overlapping. |
+ bool is_sparse_file_ = false; |
+ |
net::NetLogWithSource net_log_; |
DISALLOW_COPY_AND_ASSIGN(BaseFile); |