diff options
Diffstat (limited to 'buffer.c')
-rw-r--r-- | buffer.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/buffer.c b/buffer.c new file mode 100644 index 0000000..92d72b1 --- /dev/null +++ b/buffer.c @@ -0,0 +1,226 @@ +#include <unistd.h> +#include "buffer.h" +#include "str.h" +#include "byte.h" +#include "error.h" + +/** + @file buffer.c + @author djb + @brief input/output routines +*/ + +void buffer_init(buffer *s,ssize_t (*op)(),int fd,char *buf,size_t len) +{ + s->x = buf; + s->fd = fd; + s->op = op; + s->p = 0; + s->n = len; +} + +ssize_t buffer_0_read(int fd,char *buf,size_t len) +{ + if (buffer_flush(buffer_1) == -1) return -1; + return read(fd,buf,len); +} + +char buffer_0_space[BUFFER_INSIZE]; +static buffer it0 = BUFFER_INIT(buffer_0_read,0,buffer_0_space,sizeof(buffer_0_space)); +buffer *buffer_0 = &it0; + +char buffer_1_space[BUFFER_OUTSIZE]; +static buffer it1 = BUFFER_INIT(write,1,buffer_1_space,sizeof(buffer_1_space)); +buffer *buffer_1 = &it1; + +char buffer_2_space[BUFFER_OUTSIZE]; +static buffer it2 = BUFFER_INIT(write,2,buffer_2_space,sizeof(buffer_2_space)); +buffer *buffer_2 = &it2; + +char buffer_0_small[BUFFER_SMALL]; +static buffer is0 = BUFFER_INIT(buffer_0_read,0,buffer_0_small,sizeof(buffer_0_small)); +buffer *buffer_0small = &is0; + +char buffer_1_small[BUFFER_SMALL]; +static buffer is1 = BUFFER_INIT(write,1,buffer_1_small,sizeof(buffer_1_small)); +buffer *buffer_1small = &is1; + +char buffer_2_small[BUFFER_SMALL]; +static buffer is2 = BUFFER_INIT(write,2,buffer_2_small,sizeof(buffer_2_small)); +buffer *buffer_2small = &is2; + +ssize_t buffer_unixread(int fd,char *buf,size_t len) +{ + return read(fd,buf,len); +} + +ssize_t buffer_unixwrite(int fd,char *buf,size_t len) +{ + return write(fd,buf,len); +} + +int buffer_copy(buffer *bout,buffer *bin) +{ + int n; + char *x; + + for (;;) { + n = buffer_feed(bin); + if (n < 0) return -2; + if (!n) return 0; + x = buffer_PEEK(bin); + if (buffer_put(bout,x,n) == -1) return -3; + buffer_SEEK(bin,n); + } +} + +static int oneread(ssize_t (*op)(),int fd,char *buf,size_t len) +{ + int r; + + for (;;) { + r = op(fd,buf,len); + if (r == -1) if (errno == EINTR) continue; + return r; + } +} + +static int getthis(buffer *s,char *buf,size_t 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,size_t 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,size_t 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,size_t len) +{ + s->n += len; + s->p -= len; +} + +static int allwrite(ssize_t (*op)(),int fd,const char *buf,size_t len) +{ + int w; + + while (len) { + w = op(fd,buf,len); + if (w == -1) { + if (errno == EINTR) continue; + return -1; /* note that some data may have been written */ + } + if (w == 0) /* luser's fault */ + ; + buf += w; + len -= w; + } + return 0; +} + +int buffer_flush(buffer *s) +{ + int p; + + p = s->p; + if (!p) return 0; + s->p = 0; + return allwrite(s->op,s->fd,s->x,p); +} + +int buffer_putalign(buffer *s,const char *buf,size_t len) +{ + unsigned int n; + + while (len > (n = s->n - s->p)) { + byte_copy(s->x + s->p,n,buf); s->p += n; buf += n; len -= n; + if (buffer_flush(s) == -1) return -1; + } + /* now len <= s->n - s->p */ + byte_copy(s->x + s->p,len,buf); + s->p += len; + return 0; +} + +int buffer_put(buffer *s,const char *buf,size_t len) +{ + unsigned int n; + + n = s->n; + if (len > n - s->p) { + if (buffer_flush(s) == -1) return -1; + /* now s->p == 0 */ + if (n < BUFFER_OUTSIZE) n = BUFFER_OUTSIZE; + while (len > s->n) { + if (n > len) n = len; + if (allwrite(s->op,s->fd,buf,n) == -1) return -1; + buf += n; + len -= n; + } + } + /* now len <= s->n - s->p */ + byte_copy(s->x + s->p,len,buf); + s->p += len; + return 0; +} + +int buffer_putflush(buffer *s,const char *buf,size_t len) +{ + if (buffer_flush(s) == -1) return -1; + return allwrite(s->op,s->fd,buf,len); +} + +int buffer_putsalign(buffer *s,const char *buf) +{ + return buffer_putalign(s,buf,str_len(buf)); +} + +int buffer_puts(buffer *s,const char *buf) +{ + return buffer_put(s,buf,str_len(buf)); +} + +int buffer_putsflush(buffer *s,const char *buf) +{ + return buffer_putflush(s,buf,str_len(buf)); +} |