diff --git a/include/libvirt/libvirt-stream.h b/include/libvirt/libvirt-stream.h index feaa8ad648..c4baaf7a3d 100644 --- a/include/libvirt/libvirt-stream.h +++ b/include/libvirt/libvirt-stream.h @@ -45,6 +45,10 @@ int virStreamRecv(virStreamPtr st, char *data, size_t nbytes); +typedef enum { + VIR_STREAM_RECV_STOP_AT_HOLE = (1 << 0), +} virStreamRecvFlagsValues; + int virStreamRecvFlags(virStreamPtr st, char *data, size_t nbytes, diff --git a/src/libvirt-stream.c b/src/libvirt-stream.c index dc0dc9ea37..bedb6159a8 100644 --- a/src/libvirt-stream.c +++ b/src/libvirt-stream.c @@ -290,7 +290,7 @@ virStreamRecv(virStreamPtr stream, * @stream: pointer to the stream object * @data: buffer to read into from stream * @nbytes: size of @data buffer - * @flags: extra flags; not used yet, so callers should always pass 0 + * @flags: bitwise-OR of virStreamRecvFlagsValues * * Reads a series of bytes from the stream. This method may * block the calling application for an arbitrary amount @@ -300,6 +300,33 @@ virStreamRecv(virStreamPtr stream, * @flags. Calling this function with no @flags set (equal to * zero) is equivalent to calling virStreamRecv(stream, data, nbytes). * + * If flag VIR_STREAM_RECV_STOP_AT_HOLE is set, this function + * will stop reading from stream if it has reached a hole. In + * that case, -3 is returned and virStreamRecvHole() should be + * called to get the hole size. An example using this flag might + * look like this: + * + * while (1) { + * char buf[4096]; + * + * int ret = virStreamRecvFlags(st, buf, len, VIR_STREAM_STOP_AT_HOLE); + * if (ret < 0) { + * if (ret == -3) { + * long long len; + * ret = virStreamRecvHole(st, &len, 0); + * if (ret < 0) { + * ...error.. + * } else { + * ...seek len bytes in target... + * } + * } else { + * return -1; + * } + * } else { + * ...write buf to target... + * } + * } + * * Returns 0 when the end of the stream is reached, at * which time the caller should invoke virStreamFinish() * to get confirmation of stream completion. @@ -310,6 +337,9 @@ virStreamRecv(virStreamPtr stream, * * Returns -2 if there is no data pending to be read & the * stream is marked as non-blocking. + * + * Returns -3 if there is a hole in stream and caller requested + * to stop at a hole. */ int virStreamRecvFlags(virStreamPtr stream, @@ -331,6 +361,8 @@ virStreamRecvFlags(virStreamPtr stream, ret = (stream->driver->streamRecvFlags)(stream, data, nbytes, flags); if (ret == -2) return -2; + if (ret == -3) + return -3; if (ret < 0) goto error; return ret;