Provides seeking support in data streams.
Inherits from:
nsISupports
Last changed in Gecko 1.7 Method overview
void seek(in long whence, in long long offset); |
void setEOF(); |
long long tell(); |
Constants
| Constant | Value | Description |
NS_SEEK_SET |
0 |
Specifies that the offset is relative to the start of the stream. |
NS_SEEK_CUR |
1 |
Specifies that the offset is relative to the current position in the stream. |
NS_SEEK_END |
2 |
Specifies that the offset is relative to the end of the stream. |
Methods
seek()
This method moves the stream offset of the stream implementing this interface.
void seek( in long whence, in long long offset );
Parameters
-
whence - Specifies how to interpret the 'offset' parameter in setting the stream offset associated with the implementing stream, according to the table of constants above.
-
offset - Specifies a value, in bytes, that is used in conjunction with the 'whence' parameter to set the stream offset of the implementing stream. A negative value causes seeking in the reverse direction.
Exceptions thrown
-
NS_BASE_STREAM_CLOSED - If called on a closed stream.
setEOF()
This method truncates the stream at the current offset.
void setEOF();
Parameters
None.
Exceptions thrown
-
NS_BASE_STREAM_CLOSED - If called on a closed stream.
tell()
This method reports the current offset, in bytes, from the start of the stream.
long long tell();
Parameters
None.
Return value
The current offset, in bytes, from the start of the stream.
Exceptions thrown
-
NS_BASE_STREAM_CLOSED - If called on a closed stream.