Mercurial > hg > cdb
diff buffer_get.c @ 0:2cb46628feec
from cdb-0.75 per http://cr.yp.to/cdb.html,
retrieved 2025-01-03,
contents appear to have been create on 2000-02-19
| author | Henry S. Thompson <ht@inf.ed.ac.uk> |
|---|---|
| date | Wed, 29 Jan 2025 10:50:34 +0000 |
| parents | |
| children | 3bfef1f22a97 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/buffer_get.c Wed Jan 29 10:50:34 2025 +0000 @@ -0,0 +1,67 @@ +#include "buffer.h" +#include "byte.h" +#include "error.h" + +static int oneread(int (*op)(),int fd,char *buf,unsigned int len) +{ + int r; + + for (;;) { + r = op(fd,buf,len); + if (r == -1) if (errno == error_intr) continue; + return r; + } +} + +static int getthis(buffer *s,char *buf,unsigned int len) +{ + if (len > s->p) len = s->p; + s->p -= len; + byte_copy(buf,len,s->x + s->n); + s->n += len; + return len; +} + +int buffer_feed(buffer *s) +{ + int r; + + if (s->p) return s->p; + r = oneread(s->op,s->fd,s->x,s->n); + if (r <= 0) return r; + s->p = r; + s->n -= r; + if (s->n > 0) byte_copyr(s->x + s->n,r,s->x); + return r; +} + +int buffer_bget(buffer *s,char *buf,unsigned int len) +{ + int r; + + if (s->p > 0) return getthis(s,buf,len); + if (s->n <= len) return oneread(s->op,s->fd,buf,s->n); + r = buffer_feed(s); if (r <= 0) return r; + return getthis(s,buf,len); +} + +int buffer_get(buffer *s,char *buf,unsigned int len) +{ + int r; + + if (s->p > 0) return getthis(s,buf,len); + if (s->n <= len) return oneread(s->op,s->fd,buf,len); + r = buffer_feed(s); if (r <= 0) return r; + return getthis(s,buf,len); +} + +char *buffer_peek(buffer *s) +{ + return s->x + s->n; +} + +void buffer_seek(buffer *s,unsigned int len) +{ + s->n += len; + s->p -= len; +}
