Implement src/buffer.c

include/patty/buffer.h

@@ -0,0 +1,16 @@
+#ifndef _PATTY_BUFFER_H
+#define _PATTY_BUFFER_H
+
+typedef struct _patty_buffer patty_buffer;
+
+patty_buffer *patty_buffer_new(size_t size);
+
+void patty_buffer_destroy(patty_buffer *buffer);
+
+void *patty_buffer_data(patty_buffer *buffer);
+
+ssize_t patty_buffer_fill(patty_buffer *buffer, void *data, size_t len);
+
+void patty_buffer_flush(patty_buffer *buffer, size_t len);
+
+#endif /* _PATTY_BUFFER_H */

src/Makefile

@@ -7,10 +7,11 @@ CC		= $(CROSS)cc
 CFLAGS		= $(CGFLAGS) -fPIC -Wall -O2 -I$(INCLUDE_PATH)
 LDFLAGS		=
 
-HEADERS		= kiss.h ax25.h ax25/if.h ax25/macros.h ax25/proto.h \
+HEADERS		= buffer.h kiss.h ax25.h ax25/if.h ax25/macros.h ax25/proto.h \
 		  ax25/address.h ax25/frame.h list.h hash.h dict.h
 
-OBJS		= kiss.o ax25.o if.o address.o frame.o list.o hash.o dict.o
+OBJS		= buffer.o kiss.o ax25.o if.o address.o frame.o \
+		  list.o hash.o dict.o
 
 EXAMPLES	= iflist decode
 

src/buffer.c

@@ -0,0 +1,81 @@
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <errno.h>
+
+#include <patty/buffer.h>
+
+struct _patty_buffer {
+    void * data;
+    size_t size;
+    size_t len;
+};
+
+patty_buffer *patty_buffer_new(size_t size) {
+    patty_buffer *buffer;
+
+    if ((buffer = malloc(sizeof(*buffer))) == NULL) {
+        goto error_malloc_buffer;
+    }
+
+    if ((buffer->data = malloc(size)) == NULL) {
+        goto error_malloc_buffer_data;
+    }
+
+    buffer->size = size;
+    buffer->len  = 0;
+
+    return buffer;
+
+error_malloc_buffer_data:
+    free(buffer);
+
+error_malloc_buffer:
+    return NULL;
+}
+
+void patty_buffer_destroy(patty_buffer *buffer) {
+    free(buffer->data);
+    free(buffer);
+}
+
+void *patty_buffer_data(patty_buffer *buffer) {
+    return buffer->data;
+}
+
+ssize_t patty_buffer_fill(patty_buffer *buffer, void *data, size_t len) {
+    if (len == 0) {
+        return 0;
+    }
+
+    if (len > buffer->size - buffer->len) {
+        errno = EIO;
+
+        goto error_io;
+    }
+
+    memcpy(((unsigned char *)buffer->data) + buffer->len, data, len);
+
+    buffer->len += len;
+
+    return len;
+
+error_io:
+    return -1;
+}
+
+void patty_buffer_flush(patty_buffer *buffer, size_t len) {
+    /*
+     * Move everything from the buffer not processed up to this point, to the
+     * beginning of the buffer.
+     */
+    memmove(buffer->data,
+        ((unsigned char *)buffer->data) + len,
+        buffer->len - len);
+
+    /*
+     * Then, decrement the buffer length by the number of bytes already
+     * processed.
+     */
+    buffer->len -= len;
+}