/* -*-c-*-
*
- * $Id: lbuf.c,v 1.2 1999/05/17 20:36:08 mdw Exp $
+ * $Id: lbuf.c,v 1.5 2001/02/03 16:23:33 mdw Exp $
*
* Block-to-line buffering
*
/*----- Revision history --------------------------------------------------*
*
* $Log: lbuf.c,v $
+ * Revision 1.5 2001/02/03 16:23:33 mdw
+ * Bug fix: handle a disable during a close-induced flush without dumping
+ * core.
+ *
+ * Revision 1.4 2000/06/17 10:38:14 mdw
+ * Add support for variable buffer sizes.
+ *
+ * Revision 1.3 1999/05/22 13:38:50 mdw
+ * Fix bug which discarded initial portions of incomplete lines.
+ *
* Revision 1.2 1999/05/17 20:36:08 mdw
* Make the magical constants for the buffer flags uppercase.
*
/*----- Header files ------------------------------------------------------*/
+#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include "alloc.h"
+#include "arena.h"
#include "lbuf.h"
/*----- Main code ---------------------------------------------------------*/
char *base; /* Base address of current line */
int cr; /* Carriage return state */
+ if (b->f & LBUF_CLOSE) {
+ b->func(0, b->p);
+ return;
+ }
+
/* --- Initialize variables as necessary --- */
if (!p) {
/* --- Clear @base@ if I'm discarding an overlong line --- */
- if (b->len == sizeof(b->buf))
+ if (b->len == b->sz)
base = 0;
else
base = b->buf;
if (base) {
size_t len = l - base;
- if (len == sizeof(b->buf)) {
+ if (len == b->sz) {
b->buf[len - 1] = 0;
b->func(base, b->p);
} else if (base != b->buf)
* Use: Empties the buffer of any data currently lurking in it, and
* informs the client that this has happened. It's assumed that
* the buffer is enabled: you shouldn't be reading close events
- * on disabled buffers.
+ * on disabled buffers. The buffer, if allocated, is freed.
*/
void lbuf_close(lbuf *b)
{
- if (b->len && b->len != sizeof(b->buf)) {
+ if (b->len && b->len != b->sz) {
b->buf[b->len] = 0;
b->func(b->buf, b->p);
}
+ if (b->buf) {
+ x_free(b->a, b->buf);
+ b->buf = 0;
+ }
+ b->f |= LBUF_CLOSE;
if (b->f & LBUF_ENABLE)
b->func(0, b->p);
}
*
* Use: Returns the free portion of a line buffer. Data can then be
* written to this portion, and split out into lines by calling
- * @lbuf_flush@.
+ * @lbuf_flush@. A buffer is allocated if none currently
+ * exists.
*/
size_t lbuf_free(lbuf *b, char **p)
*
* If a line from the file wouldn't fit in the buffer, I truncate it and
* return what would fit. The rest of the line ought to be discarded.
- * This condition is signalled by @len = sizeof(buf)@, and means that the
- * entire buffer is OK to be trashed. In other cases, @len@ is the amount
- * of space currently occupied in the buffer. This special case is the
- * reason this routine exists.
+ * This condition is signalled by @len = b->sz@, and means that the entire
+ * buffer is OK to be trashed. In other cases, @len@ is the amount of
+ * space currently occupied in the buffer. This special case is the reason
+ * this routine exists.
*/
- if (b->len == 0 || b->len == sizeof(b->buf)) {
+ if (b->len != 0 && b->len != b->sz) {
*p = b->buf + b->len;
- return (sizeof(b->buf) - b->len);
+ return (b->sz - b->len);
} else {
+ if (!b->buf)
+ b->buf = x_alloc(b->a, b->sz);
*p = b->buf;
- return (sizeof(b->buf));
+ return (b->sz);
}
}
void lbuf_snarf(lbuf *b, const void *p, size_t sz)
{
const char *pp = p;
- while (sz) {
+ while (sz && (b->f & LBUF_ENABLE)) {
size_t bsz;
char *bp;
}
}
+/* --- @lbuf_setsize@ --- *
+ *
+ * Arguments: @lbuf *b@ = pointer to buffer block
+ * @size_t sz@ = requested maximum line size
+ *
+ * Returns: ---
+ *
+ * Use: Modifies the size of the buffer associated with the block.
+ * It is an error to resize a buffer while it contains data.
+ */
+
+void lbuf_setsize(lbuf *b, size_t sz)
+{
+ if (b->buf)
+ assert(((void)"Buffer in use in lbuf_setsize",
+ b->len == 0 || b->len == b->sz));
+ if (b->buf)
+ x_free(b->a, b->buf);
+ b->sz = sz;
+ b->buf = 0;
+}
+
/* --- @lbuf_init@ --- *
*
* Arguments: @lbuf *b@ = pointer to buffer block
* Returns: ---
*
* Use: Initializes a line buffer block. Any recognized lines are
- * passed to @func@ for processing.
+ * passed to @func@ for processing. No buffer is initially
+ * allocated; this is done when the buffer is actually required
+ * for the first time.
*/
void lbuf_init(lbuf *b,
b->p = p;
b->len = 0;
b->f = LBUF_ENABLE;
+ b->buf = 0;
+ b->a = arena_global;
+ lbuf_setsize(b, 256);
+}
+
+/* --- @lbuf_destroy@ --- *
+ *
+ * Arguments: @lbuf *b@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Deallocates a line buffer and frees any resources it owned.
+ */
+
+void lbuf_destroy(lbuf *b)
+{
+ if (b->buf) {
+ x_free(b->a, b->buf);
+ b->buf = 0;
+ }
}
/*----- That's all, folks -------------------------------------------------*/
~mdw / mLib / blobdiff