From: Yousong Zhou Date: Wed, 21 Jan 2015 13:21:25 +0000 (+0800) Subject: ustream: add function ustream_read(). X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=60236c485387d33e1d02398a953a0834ad125161;p=oweals%2Flibubox.git ustream: add function ustream_read(). It can be used to fill caller-specified buffer with data already in ustream read buffer. Useful in the following use pattern. int available = ustream_pending_data(s, false); if (available >= sizeof(struct msghdr)) { struct msghdr h; ustream_read(s, &h, sizeof(h)); } Signed-off-by: Yousong Zhou --- diff --git a/ustream.c b/ustream.c index 828a025..fc93bc2 100644 --- a/ustream.c +++ b/ustream.c @@ -333,6 +333,26 @@ char *ustream_get_read_buf(struct ustream *s, int *buflen) return data; } +int ustream_read(struct ustream *s, char *buf, int buflen) +{ + char *chunk; + int chunk_len; + int len = 0; + + do { + chunk = ustream_get_read_buf(s, &chunk_len); + if (!chunk) + break; + if (chunk_len > buflen - len) + chunk_len = buflen - len; + memcpy(buf + len, chunk, chunk_len); + ustream_consume(s, chunk_len); + len += chunk_len; + } while (len < buflen); + + return len; +} + static void ustream_write_error(struct ustream *s) { if (!s->write_error) diff --git a/ustream.h b/ustream.h index 6431744..53e0828 100644 --- a/ustream.h +++ b/ustream.h @@ -143,6 +143,11 @@ void ustream_free(struct ustream *s); /* ustream_consume: remove data from the head of the read buffer */ void ustream_consume(struct ustream *s, int len); +/* + * ustream_read: read and consume data in read buffer into caller-specified + * area. Return length of data read. + */ +int ustream_read(struct ustream *s, char *buf, int buflen); /* ustream_write: add data to the write buffer */ int ustream_write(struct ustream *s, const char *buf, int len, bool more); int ustream_printf(struct ustream *s, const char *format, ...);