An input stream that allows you to read from a slice of a file.
Initialize with a file and new start/end positions. Both start and
start+length must be smaller than the size of the file. Not doing so
will lead to undefined behavior.
You must initialize the stream, and only initialize it once, before it
can be used.
| file | file to read from |
| start | start offset of slice to read. Must be smaller than the size of the file. |
| length | length of slice to read. Must be small enough that start+length is smaller than the size of the file. |
| ioFlags | file open flags listed in prio.h (see PR_Open documentation) or -1 to open the file in default mode (PR_RDONLY). |
| perm | file mode bits listed in prio.h or -1 to use the default value (0) |
| behaviorFlags | flags specifying various behaviors of the class (see enumerations in nsIFileInputStream) |