ucx/buffer.h

changeset 1
1bcaac272cdf
child 5
88625853ae74
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ucx/buffer.h	Fri Nov 30 21:18:13 2012 +0100
@@ -0,0 +1,100 @@
+#ifndef BUFFER_H
+#define	BUFFER_H
+
+#include "ucx.h"
+#include <sys/types.h>
+#include <stdio.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#define UCX_BUFFER_DEFAULT      0x00
+#define UCX_BUFFER_AUTOFREE     0x01
+/* the buffer may automatically double its size on write operations */
+#define UCX_BUFFER_AUTOEXTEND   0x02
+
+/* the user shall not modify values, but may get the latest pointer */
+typedef struct {
+    char *space;
+    size_t pos;
+    size_t capacity;
+    size_t size;
+    int flags;
+} UcxBuffer;
+
+/* if space is NULL, new space is allocated and the autofree flag is enforced */
+UcxBuffer *ucx_buffer_new(void *space, size_t size, int flags);
+void ucx_buffer_free(UcxBuffer* buffer);
+
+/*
+ * the autofree flag is enforced for the new buffer
+ * if length is zero, the whole remaining buffer shall be extracted
+ * the position of the new buffer is set to zero
+ */
+UcxBuffer* ucx_buffer_extract(UcxBuffer *src,
+        size_t start, size_t length, int flags);
+#define ucx_buffer_clone(src,flags) \
+    ucx_buffer_extract(src, 0, 0, flags)
+
+/*
+ * Moves the position of the buffer to a new position relative to whence.
+ *
+ * SEEK_SET marks the start of the buffer
+ * SEEK_CUR marks the current position
+ * SEEK_END marks the first 0-byte in the buffer
+ *
+ * ucx_memseek returns 0 on success and -1 if the new position is beyond the
+ * bounds of the allocated buffer. In that case the position of the buffer
+ * remains unchanged.
+ *
+ */
+int ucx_buffer_seek(UcxBuffer *buffer, off_t offset, int whence);
+
+/*
+ * returns non-zero, if the current buffer position has exceeded the last
+ * available byte of the underlying buffer
+ *
+ */
+int ucx_buffer_eof(UcxBuffer *buffer);
+
+
+int ucx_buffere_extend(UcxBuffer *buffer, size_t len);
+
+size_t ucx_buffer_write(const void *ptr, size_t size, size_t nitems,
+        UcxBuffer *buffer);
+
+size_t ucx_buffer_read(void *ptr, size_t size, size_t nitems,
+        UcxBuffer *buffer);
+
+/* when autoextend is enabled, ensure you get the latest pointer to the data */
+//define ucx_buffer_write(data, itemsize, nitems, buffer) \
+//    ucx_bufio(data, itemsize, nitems, buffer, 0)
+//define ucx_buffer_read(data, itemsize, nitems, buffer) \
+//        ucx_bufio(data, itemsize, nitems, buffer, 1)
+int ucx_buffer_putc(UcxBuffer *b, int c);
+int ucx_buffer_getc(UcxBuffer *b);
+
+
+/*
+ * copies all bytes from s1 to s2
+ * uses the read function r to read from s1 und writes the data using the
+ * write function w to s2
+ * returns the number of bytes copied
+ */
+size_t ucx_buffer_generic_copy(void *s1, void *s2, read_func r, write_func w,
+        size_t bufsize);
+
+
+#define UCX_DEFAULT_BUFFER_SIZE 0x4000000
+
+#define ucx_buffer_copy(s1,s2,r,w) \
+    ucx_buffer_generic_copy(s1, s2, (read_func)r, (write_func)w, \
+    UCX_DEFAULT_BUFFER_SIZE)
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* BUFFER_H */
+

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