Commit b4e04fb6 authored by Stefan Beller's avatar Stefan Beller Committed by Junio C Hamano

strbuf: add strbuf_read_once to read without blocking

The new call will read from a file descriptor into a strbuf once. The
underlying call xread is just run once. xread only reattempts
reading in case of EINTR, which makes it suitable to use for a
nonblocking read.
Signed-off-by: Stefan Beller's avatarStefan Beller <sbeller@google.com>
Signed-off-by: default avatarJunio C Hamano <gitster@pobox.com>
parent 1079c4be
......@@ -384,6 +384,17 @@ ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
return sb->len - oldlen;
}
ssize_t strbuf_read_once(struct strbuf *sb, int fd, size_t hint)
{
ssize_t cnt;
strbuf_grow(sb, hint ? hint : 8192);
cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
if (cnt > 0)
strbuf_setlen(sb, sb->len + cnt);
return cnt;
}
#define STRBUF_MAXLINK (2*PATH_MAX)
int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
......
......@@ -366,6 +366,14 @@ extern size_t strbuf_fread(struct strbuf *, size_t, FILE *);
*/
extern ssize_t strbuf_read(struct strbuf *, int fd, size_t hint);
/**
* Read the contents of a given file descriptor partially by using only one
* attempt of xread. The third argument can be used to give a hint about the
* file size, to avoid reallocs. Returns the number of new bytes appended to
* the sb.
*/
extern ssize_t strbuf_read_once(struct strbuf *, int fd, size_t hint);
/**
* Read the contents of a file, specified by its path. The third argument
* can be used to give a hint about the file size, to avoid reallocs.
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment