hdfsWrite()
Supported by libMapRClient for hadoop-2.x
Writes to the specified open file.
If the file is opened in write-only mode, writes start at offset 0 because write-only mode causes the content of the file to be truncated when the file is opened.
If the file is opened in append mode, data is appended to the end of the file.
If there are concurrent writes that start at the same offset, only the last write to finish persists.
If a call to hdfsSeek() moves the
offset past the end of the file before a call to
hdfsWrite(), the result is a hole in the file
between the previous end of the file and the offset at which the
write begins.
You can obtain the size of a file in bytes by
calling hdfsGetPathInfo().
Flushes to the server happen automatically at
intervals during a write operation. After a write operation is
finished, either call hdfsFlush() explicitly or call
hdfsFlush() implicitly by calling
hdfsCloseFile() to be sure that any data remaining in
the write buffer is flushed.
On error, pending write buffers are flushed to the server.
Signature
tsize hdfsWrite(hdfsFS fs, hdfsFile file, const void* buffer, tSize length)Parameters
| Parameter | Description |
|---|---|
| fs | The handle of the file system where the file is located. Obtain this
handle with one of the hdfsConnect() APIs. |
| file | The handle of the file. Obtain this handle with
one of the hdfsOpenFile() APIs. |
| buffer | The buffer containing the data to be written. |
| length | The number of bytes to write. This value cannot
be zero. The maximum length of the buffer is the maximum size of
the tSize data type. |
Return Value
Returns the number of bytes written, -1 on error.
Check errno for error codes and meanings.