Writes a chunk of bytes from a blob to the BLOB accessible through this, blob
is unchanged after this call.
If blob has an associated BlobOp (ie. if blob.
op is not null) then the data to be written using
this is the data fetched using blob.op.
| this |
a BlobOp |
| blob |
a Blob which contains the data to write |
| offset |
offset to write from the start of the blob (starts at 0) |
|
the number of bytes written. In case of error, -1 is returned and the provider should have added an error to the connection. |