Libc-825.24.tar.gz

[apple/libc.git] / regex / TRE / lib / tre-stack.c

diff --git a/regex/TRE/lib/tre-stack.c b/regex/TRE/lib/tre-stack.c
new file mode 100644 (file)
index 0000000..8ad89c8
--- /dev/null
+++ b/regex/TRE/lib/tre-stack.c
@@ -0,0 +1,125 @@
+/*
+  tre-stack.c - Simple stack implementation
+
+  This software is released under a BSD-style license.
+  See the file LICENSE for details and copyright.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+#include <stdlib.h>
+#include <assert.h>
+
+#include "tre-internal.h"
+#include "tre-stack.h"
+#include "xmalloc.h"
+
+union tre_stack_item {
+  void *voidptr_value;
+  int int_value;
+};
+
+struct tre_stack_rec {
+  int size;
+  int max_size;
+  int increment;
+  int ptr;
+  union tre_stack_item *stack;
+};
+
+
+tre_stack_t *
+tre_stack_new(int size, int max_size, int increment)
+{
+  tre_stack_t *s;
+
+  s = xmalloc(sizeof(*s));
+  if (s != NULL)
+    {
+      s->stack = xmalloc(sizeof(*s->stack) * size);
+      if (s->stack == NULL)
+       {
+         xfree(s);
+         return NULL;
+       }
+      s->size = size;
+      s->max_size = max_size;
+      s->increment = increment;
+      s->ptr = 0;
+    }
+  return s;
+}
+
+void
+tre_stack_destroy(tre_stack_t *s)
+{
+  xfree(s->stack);
+  xfree(s);
+}
+
+int
+tre_stack_num_objects(tre_stack_t *s)
+{
+  return s->ptr;
+}
+
+static reg_errcode_t
+tre_stack_push(tre_stack_t *s, union tre_stack_item value)
+{
+  if (s->ptr < s->size)
+    {
+      s->stack[s->ptr] = value;
+      s->ptr++;
+    }
+  else
+    {
+      if (s->size >= s->max_size)
+       {
+         DPRINT(("tre_stack_push: stack full\n"));
+         return REG_ESPACE;
+       }
+      else
+       {
+         union tre_stack_item *new_buffer;
+         int new_size;
+         DPRINT(("tre_stack_push: trying to realloc more space\n"));
+         new_size = s->size + s->increment;
+         if (new_size > s->max_size)
+           new_size = s->max_size;
+         new_buffer = xrealloc(s->stack, sizeof(*new_buffer) * new_size);
+         if (new_buffer == NULL)
+           {
+             DPRINT(("tre_stack_push: realloc failed.\n"));
+             return REG_ESPACE;
+           }
+         DPRINT(("tre_stack_push: realloc succeeded.\n"));
+         assert(new_size > s->size);
+         s->size = new_size;
+         s->stack = new_buffer;
+         tre_stack_push(s, value);
+       }
+    }
+  return REG_OK;
+}
+
+#define define_pushf(typetag, type)  \
+  declare_pushf(typetag, type) {     \
+    union tre_stack_item item;      \
+    item.typetag ## _value = value;  \
+    return tre_stack_push(s, item);  \
+}
+
+define_pushf(int, int)
+define_pushf(voidptr, void *)
+
+#define define_popf(typetag, type)                 \
+  declare_popf(typetag, type) {                            \
+    return s->stack[--s->ptr].typetag ## _value;    \
+  }
+
+define_popf(int, int)
+define_popf(voidptr, void *)
+
+/* EOF */