1 files changed, 226 insertions, 0 deletions
diff --git a/src/buffer.c b/src/buffer.c
new file mode 100644
index 0000000..06e3857
--- /dev/null
+++ b/src/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;
+}
+
+static 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);
+}
+
+ssize_t buffer_unixread(int fd,char *buf,size_t len)
+{
+  return (ssize_t) read(fd,buf,len);
+}
+
+ssize_t buffer_unixwrite(int fd,char *buf,size_t len)
+{
+  return (ssize_t) write(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(buffer_unixwrite,1,buffer_1_space,sizeof(buffer_1_space));
+buffer *buffer_1 = &it1;
+
+char buffer_2_space[BUFFER_OUTSIZE];
+static buffer it2 = BUFFER_INIT(buffer_unixwrite,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(buffer_unixwrite,1,buffer_1_small,sizeof(buffer_1_small));
+buffer *buffer_1small = &is1;
+
+char buffer_2_small[BUFFER_SMALL];
+static buffer is2 = BUFFER_INIT(buffer_unixwrite,2,buffer_2_small,sizeof(buffer_2_small));
+buffer *buffer_2small = &is2;
+
+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));
+}