1 files changed, 148 insertions, 0 deletions
diff --git a/common/ccparray.c b/common/ccparray.c
new file mode 100644
index 0000000..ff3eb40
--- /dev/null
+++ b/common/ccparray.c
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+/* ccparray.c - A simple dynamic array for character pointer.
+ * Copyright (C) 2016 g10 Code GmbH
+ *
+ * This file is part of GnuPG.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either
+ *
+ *   - the GNU Lesser General Public License as published by the Free
+ *     Software Foundation; either version 3 of the License, or (at
+ *     your option) any later version.
+ *
+ * or
+ *
+ *   - the GNU General Public License as published by the Free
+ *     Software Foundation; either version 2 of the License, or (at
+ *     your option) any later version.
+ *
+ * or both in parallel, as here.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <stdarg.h>
+
+#include "util.h"
+#include "ccparray.h"
+
+
+/* A simple implementation of a dynamic array of const char pointers.
+ * The example code:
+ *
+ *   ccparray_t ccp;
+ *   const char **argv;
+ *   int i;
+ *
+ *   ccparray_init (&ccp, 0);
+ *   ccparray_put (&ccp, "First arg");
+ *   ccparray_put (&ccp, "Second arg");
+ *   ccparray_put (&ccp, NULL);
+ *   ccparray_put (&ccp, "Fourth arg");
+ *   argv = ccparray_get (&ccp, NULL);
+ *   if (!argv)
+ *     die ("error building array: %s\n", strerror (errno));
+ *   for (i=0; argv[i]; i++)
+ *     printf ("[%d] = '%s'\n", i, argv[i]);
+ *   xfree (argv);
+ *
+ * will result in this output:
+ *
+ *   [0] = 'First arg'
+ *   [1] = 'Second arg'
+ *
+ * Note that allocation errors are detected but only returned with the
+ * final ccparray_get(); this helps not to clutter the code with out
+ * of core checks.
+ */
+
+void
+ccparray_init (ccparray_t *cpa, unsigned int initialsize)
+{
+  if (!initialsize)
+    cpa->size = 16;
+  else if (initialsize < (1<<16))
+    cpa->size = initialsize;
+  else
+    cpa->size = (1<<16);
+
+  cpa->count = 0;
+  cpa->out_of_core = 0;
+  cpa->array = xtrycalloc (cpa->size, sizeof *cpa->array);
+  if (!cpa->array)
+    cpa->out_of_core = errno;
+}
+
+
+void
+ccparray_put (ccparray_t *cpa, const char *value)
+{
+  if (cpa->out_of_core)
+    return;
+
+  if (cpa->count + 1 >= cpa->size)
+    {
+      const char **newarray;
+      size_t n, newsize;
+
+      if (cpa->size < 8)
+        newsize = 16;
+      else if (cpa->size < 4096)
+        newsize = 2 * cpa->size;
+      else if (cpa->size < (1<<16))
+        newsize = cpa->size + 2048;
+      else
+        {
+          cpa->out_of_core = ENOMEM;
+          return;
+        }
+
+      newarray = xtrycalloc (newsize, sizeof *newarray);
+      if (!newarray)
+        {
+          cpa->out_of_core = errno ? errno : ENOMEM;
+          return;
+        }
+      for (n=0; n < cpa->size; n++)
+        newarray[n] = cpa->array[n];
+      xfree (cpa->array);
+      cpa->array = newarray;
+      cpa->size = newsize;
+
+    }
+  cpa->array[cpa->count++] = value;
+}
+
+
+const char **
+ccparray_get (ccparray_t *cpa, size_t *r_count)
+{
+  const char **result;
+
+  if (cpa->out_of_core)
+    {
+      if (cpa->array)
+        {
+          xfree (cpa->array);
+          cpa->array = NULL;
+        }
+      gpg_err_set_errno (cpa->out_of_core);
+      return NULL;
+    }
+
+  result= cpa->array;
+  if (r_count)
+    *r_count = cpa->count;
+  cpa->array = NULL;
+  cpa->out_of_core = ENOMEM; /* hack to make sure it won't get reused. */
+  return result;
+}