1 files changed, 131 insertions, 0 deletions
diff --git a/subversion/libsvn_fs_base/key-gen.c b/subversion/libsvn_fs_base/key-gen.c
new file mode 100644
index 0000000..411207d
--- /dev/null
+++ b/subversion/libsvn_fs_base/key-gen.c
@@ -0,0 +1,131 @@
+/* key-gen.c --- manufacturing sequential keys for some db tables
+ *
+ * ====================================================================
+ *    Licensed to the Apache Software Foundation (ASF) under one
+ *    or more contributor license agreements.  See the NOTICE file
+ *    distributed with this work for additional information
+ *    regarding copyright ownership.  The ASF licenses this file
+ *    to you under the Apache License, Version 2.0 (the
+ *    "License"); you may not use this file except in compliance
+ *    with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing,
+ *    software distributed under the License is distributed on an
+ *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *    KIND, either express or implied.  See the License for the
+ *    specific language governing permissions and limitations
+ *    under the License.
+ * ====================================================================
+ */
+
+#include <assert.h>
+#include <string.h>
+
+#define APR_WANT_STRFUNC
+#include <apr_want.h>
+#include <stdlib.h>
+#include <apr.h>
+
+#include "key-gen.h"
+
+
+
+/*** Keys for reps and strings. ***/
+
+
+void
+svn_fs_base__next_key(const char *this, apr_size_t *len, char *next)
+{
+  apr_size_t olen = *len;     /* remember the first length */
+  int i = olen - 1;           /* initial index; we work backwards */
+  char c;                     /* current char */
+  svn_boolean_t carry = TRUE; /* boolean: do we have a carry or not?
+                                 We start with a carry, because we're
+                                 incrementing the number, after all. */
+
+  /* Leading zeros are not allowed, except for the string "0". */
+  if ((*len > 1) && (this[0] == '0'))
+    {
+      *len = 0;
+      return;
+    }
+
+  for (i = (olen - 1); i >= 0; i--)
+    {
+      c = this[i];
+
+      /* Validate as we go. */
+      if (! (((c >= '0') && (c <= '9')) || ((c >= 'a') && (c <= 'z'))))
+        {
+          *len = 0;
+          return;
+        }
+
+      if (carry)
+        {
+          if (c == 'z')
+            next[i] = '0';
+          else
+            {
+              carry = FALSE;
+
+              if (c == '9')
+                next[i] = 'a';
+              else
+                next[i] = c + 1;
+            }
+        }
+      else
+        next[i] = c;
+    }
+
+  /* The new length is OLEN, plus 1 if there's a carry out of the
+     leftmost digit. */
+  *len = olen + (carry ? 1 : 0);
+
+  /* Ensure that we haven't overrun the (ludicrous) bound on key length.
+     Note that MAX_KEY_SIZE is a bound on the size *including*
+     the trailing null byte. */
+  assert(*len < MAX_KEY_SIZE);
+
+  /* Now we know it's safe to add the null terminator. */
+  next[*len] = '\0';
+
+  /* Handle any leftover carry. */
+  if (carry)
+    {
+      memmove(next+1, next, olen);
+      next[0] = '1';
+    }
+}
+
+
+int
+svn_fs_base__key_compare(const char *a, const char *b)
+{
+  int a_len = strlen(a);
+  int b_len = strlen(b);
+  int cmp;
+
+  if (a_len > b_len)
+    return 1;
+  if (b_len > a_len)
+    return -1;
+  cmp = strcmp(a, b);
+  return (cmp ? (cmp / abs(cmp)) : 0);
+}
+
+
+svn_boolean_t
+svn_fs_base__same_keys(const char *a, const char *b)
+{
+  if (! (a || b))
+    return TRUE;
+  if (a && (! b))
+    return FALSE;
+  if ((! a) && b)
+    return FALSE;
+  return (strcmp(a, b) == 0);
+}