added: dynamic buffer handling

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@2425 4a8a32a2-be11-0410-ad9d-d568d2c75423

diff --git a/support/Util/dbuf.c b/support/Util/dbuf.c
new file mode 100644 (file)
index 0000000..cde35f2
--- /dev/null
+++ b/support/Util/dbuf.c
@@ -0,0 +1,259 @@
+/*
+  dbuf.c - Dynamic buffer implementation
+  version 1.1.0, March 28th, 2003
+
+  Copyright (c) 2003 Borut Razem
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Borut Razem
+  borut.razem@siol.net
+*/
+
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "dbuf.h"
+
+
+/*
+ * Assure that the buffer is large enough to hold
+ * size bytes; enlarge it if necessary.
+ */
+
+static int dbuf_expand(struct dbuf_s *dbuf, size_t size)
+{
+  assert(dbuf->alloc != 0);
+  assert(dbuf->buf != NULL);
+
+  if (dbuf->len + size > dbuf->alloc) {
+    /* new_allocated_size = current_allocated_size * 2^n */
+    /* can this be optimized? */
+    while (dbuf->len + size >= dbuf->alloc)
+      dbuf->alloc += dbuf->alloc;
+
+    if ((dbuf->buf = realloc(dbuf->buf, dbuf->alloc)) == NULL)
+      return 0;
+  }
+
+  return 1;
+}
+
+
+/*
+ * Initialize the dbuf structure and
+ * allocate buffer to hold size bytes.
+ */
+
+int dbuf_init(struct dbuf_s *dbuf, size_t size)
+{
+  assert(size != 0);
+
+  if (size == 0)
+    size = 1;
+
+  dbuf->len = 0;
+  dbuf->alloc = size;
+  return ((dbuf->buf = malloc(dbuf->alloc)) != NULL);
+}
+
+
+/*
+ * Allocate new dbuf structure on the heap
+ * and initialize it.
+ *
+ * See: dbuf_delete()
+ */
+
+struct dbuf_s *dbuf_new(size_t size)
+{
+  struct dbuf_s *dbuf;
+
+  dbuf = (struct dbuf_s *)malloc(sizeof(struct dbuf_s));
+  if (dbuf != NULL) {
+    if (dbuf_init(dbuf, size) == 0) {
+      free(dbuf);
+      return NULL;
+    }
+  }
+  return dbuf;
+}
+
+
+/*
+ * Set the buffer size. Buffer size can be only decreased.
+ */
+
+int dbuf_set_size(struct dbuf_s *dbuf, size_t size)
+{
+  assert(dbuf != NULL);
+  assert(dbuf->alloc != 0);
+  assert(size < dbuf->len);
+
+  if (size <= dbuf->len) {
+    dbuf->len = size;
+    return 1;
+  }
+
+  return 0;
+}
+
+
+/*
+ * Append the buf to the end of the buffer.
+ */
+
+int dbuf_append(struct dbuf_s *dbuf, const void *buf, size_t size)
+{
+  assert(dbuf != NULL);
+  assert(dbuf->alloc != 0);
+  assert(dbuf->buf != NULL);
+
+  if (dbuf_expand(dbuf, size) != 0) {
+    memcpy(&(((char *)dbuf->buf)[dbuf->len]), buf, size);
+    dbuf->len += size;
+    return 1;
+  }
+
+  return 0;
+}
+
+
+/*
+ * Add '\0' character at the end of the buffer without
+ * count it in the dbuf->len.
+ */
+
+const char *dbuf_c_str(struct dbuf_s *dbuf)
+{
+  assert(dbuf != NULL);
+  assert(dbuf->alloc != 0);
+  assert(dbuf->buf != NULL);
+
+  /* only if not already null terminated */
+  if (((char *)dbuf->buf)[dbuf->len] != '\0') {
+    dbuf_expand(dbuf, 1);
+    ((char *)dbuf->buf)[dbuf->len] = '\0';
+  }
+
+  return dbuf->buf;
+}
+
+
+/*
+ * Get the buffer pointer.
+ */
+
+const void *dbuf_get_buf(struct dbuf_s *dbuf)
+{
+  assert(dbuf != NULL);
+  assert(dbuf->alloc != 0);
+  assert(dbuf->buf != NULL);
+
+  return dbuf->buf;
+}
+
+
+/*
+ * Get the buffer size.
+ */
+
+size_t dbuf_get_size(struct dbuf_s *dbuf)
+{
+  assert(dbuf != NULL);
+  assert(dbuf->alloc != 0);
+  assert(dbuf->buf != NULL);
+
+  return dbuf->len;
+}
+
+
+/*
+ * Trim the allocated buffer to required size
+ */
+
+int dbuf_trim(struct dbuf_s *dbuf)
+{
+  void *buf;
+
+  assert(dbuf != NULL);
+  assert(dbuf->alloc != 0);
+  assert(dbuf->buf != NULL);
+
+  buf = realloc(dbuf->buf, dbuf->len);
+
+  if (buf != NULL) {
+    dbuf->alloc = dbuf->len;
+    dbuf->buf = buf;
+  }
+
+  return buf != NULL;
+}
+
+
+/*
+ * Detach the buffer from dbuf structure.
+ * The dbuf structure can be reused by
+ * reinitializing it.
+ *
+ * See: dbuf_init()
+ */
+
+void *dbuf_detach(struct dbuf_s *dbuf)
+{
+  void *ret;
+
+  assert(dbuf != NULL);
+  assert(dbuf->alloc != 0);
+  assert(dbuf->buf != NULL);
+
+  ret = dbuf->buf;
+  dbuf->buf = NULL;
+  dbuf->len = 0;
+  dbuf->alloc = 0;
+
+  return ret;
+}
+
+
+/*
+ * Destroy the dbuf structure and
+ * free the buffer
+ */
+
+void dbuf_destroy(struct dbuf_s *dbuf)
+{
+  free(dbuf_detach(dbuf));
+}
+
+
+/*
+ * Delete dbuf structure on the heap:
+ * destroy it and free the allocated space.
+ * The user's responsablity is not to use
+ * the pointer any more: the best think to do
+ * is to set the pointer to NULL value.
+ *
+ * See dbuf_new()
+ */
+
+void dbuf_delete(struct dbuf_s *dbuf)
+{
+  dbuf_destroy(dbuf);
+  free(dbuf);
+}

diff --git a/support/Util/dbuf.h b/support/Util/dbuf.h
new file mode 100644 (file)
index 0000000..2ac978d
--- /dev/null
+++ b/support/Util/dbuf.h
@@ -0,0 +1,64 @@
+/*
+  dbuf.h - Dynamic buffer interface
+  version 1.1.0, March 28th, 2003
+
+  Copyright (c) 2003 Borut Razem
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Borut Razem
+  borut.razem@siol.net
+*/
+
+
+#ifndef __DBUF_H
+#define __DBUF_H
+
+#ifndef _WIN32
+#include <ansidecl.h>
+#else
+#define PARAMS(paramlist)   paramlist
+#endif
+
+struct dbuf_s {
+  size_t alloc;   /* size of allocated buffer in bytes */
+  size_t len;     /* actual size of the buffer in bytes */
+  void *buf;      /* pointer to the buffer, allocated on heap */
+};
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct dbuf_s *dbuf_new PARAMS ((size_t size));
+int dbuf_init PARAMS ((struct dbuf_s *dbuf, size_t size));
+int dbuf_set_size PARAMS ((struct dbuf_s *dbuf, size_t size));
+int dbuf_append PARAMS ((struct dbuf_s *dbuf, const void *buf, size_t size));
+const void *dbuf_get_buf PARAMS ((struct dbuf_s *dbuf));
+size_t dbuf_get_size PARAMS ((struct dbuf_s *dbuf));
+const char *dbuf_c_str PARAMS ((struct dbuf_s *dbuf));
+int dbuf_trim(struct dbuf_s *dbuf);
+void *dbuf_detach PARAMS ((struct dbuf_s *dbuf));
+void dbuf_destroy PARAMS ((struct dbuf_s *dbuf));
+void dbuf_delete PARAMS ((struct dbuf_s *dbuf));
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* __DBUF_H */