Initial release of Maemo 5 port of gnuplot

[gnuplot] / src / dynarray.c

diff --git a/src/dynarray.c b/src/dynarray.c
new file mode 100644 (file)
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--- /dev/null
+++ b/src/dynarray.c
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+#ifndef lint
+static char *RCSid() { return RCSid("$Id: dynarray.c,v 1.11 2004/07/01 17:10:04 broeker Exp $"); }
+#endif
+
+/*[
+ * Copyright 1999, 2004   Hans-Bernhard Broeker
+ *
+ * Permission to use, copy, and distribute this software and its
+ * documentation for any purpose with or without fee is hereby granted,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation.
+ *
+ * Permission to modify the software is granted, but not the right to
+ * distribute the complete modified source code.  Modifications are to
+ * be distributed as patches to the released version.  Permission to
+ * distribute binaries produced by compiling modified sources is granted,
+ * provided you
+ *   1. distribute the corresponding source modifications from the
+ *    released version in the form of a patch file along with the binaries,
+ *   2. add special version identification to distinguish your version
+ *    in addition to the base release version number,
+ *   3. provide your name and address as the primary contact for the
+ *    support of your modified version, and
+ *   4. retain our contact information in regard to use of the base
+ *    software.
+ * Permission to distribute the released version of the source code along
+ * with corresponding source modifications in the form of a patch file is
+ * granted with same provisions 2 through 4 for binary distributions.
+ *
+ * This software is provided "as is" without express or implied warranty
+ * to the extent permitted by applicable law.
+]*/
+
+/* This module implements a dynamically growing array of arbitrary
+ * elements parametrized by their sizeof(). There is no 'access
+ * function', i.e. you'll have to access the elements of the
+ * dynarray->v memory block by hand. It's implemented in OO-style,
+ * even though this is C, not C++.  In particular, every function
+ * takes a pointer to a data structure type 'dynarray', which mimics
+ * the 'this' pointer of an object. */
+
+#include "dynarray.h"
+
+#include "alloc.h"
+#include "util.h"              /* for graph_error() */
+
+/* The 'constructor' of a dynarray object: initializes all the
+ * variables to well-defined startup values */
+void
+init_dynarray(dynarray *this, size_t entry_size, long size, long increment)
+{
+    this->v = 0;               /* preset value, in case gp_alloc fails */
+    if (size)
+       this->v = gp_alloc(entry_size*size, "init dynarray");
+    this->size = size;
+    this->end = 0;
+    this->increment = increment;
+    this->entry_size = entry_size;
+}
+
+/* The 'destructor'; sets all crucial elements of the structure to
+ * well-defined values to avoid problems by use of bad pointers... */
+void
+free_dynarray(dynarray *this)
+{
+    free(this->v);             /* should work, even if gp_alloc failed */
+    this->v = 0;
+    this->end = this->size = 0;
+}
+
+/* Set the size of the dynamical array to a new, fixed value */
+void
+resize_dynarray(dynarray *this, long newsize)
+{
+    if (!this->v)
+       graph_error("resize_dynarray: dynarray wasn't initialized!");
+
+    if (newsize == 0)
+       free_dynarray(this);
+    else {
+       this->v = gp_realloc(this->v, this->entry_size * newsize, "extend dynarray");
+       this->size = newsize;
+    }
+}
+
+/* Increase the size of the dynarray by a given amount */
+void
+extend_dynarray(dynarray *this, long increment)
+{
+    resize_dynarray(this, this->size + increment);
+}
+
+/* Get pointer to the element one past the current end of the dynamic
+ * array. Resize it if necessary. Returns a pointer-to-void to that
+ * element. */
+void GPHUGE *
+nextfrom_dynarray(dynarray *this)
+{
+    if (!this->v)
+       graph_error("nextfrom_dynarray: dynarray wan't initialized!");
+
+    if (this->end >= this->size)
+       extend_dynarray(this, this->increment);
+    return (void *)((char *)(this->v) + this->entry_size * (this->end++));
+}
+
+/* Release the element at the current end of the dynamic array, by
+ * moving the 'end' index one element backwards */
+void
+droplast_dynarray(dynarray *this)
+{
+    if (!this->v)
+       graph_error("droplast_dynarray: dynarray wasn't initialized!");
+
+    if (this->end)
+       this->end--;
+}