bdelta: new module for binary diff/patch

[ccan] / ccan / bdelta / bdelta.h

diff --git a/ccan/bdelta/bdelta.h b/ccan/bdelta/bdelta.h
new file mode 100644 (file)
index 0000000..67ed73d
--- /dev/null
+++ b/ccan/bdelta/bdelta.h
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2011 Joseph Adams <joeyadams3.14159@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef CCAN_BDELTA_H
+#define CCAN_BDELTA_H
+
+#include <stddef.h>
+
+typedef enum {
+       BDELTA_OK               = 0,  /* Operation succeeded. */
+
+       BDELTA_MEMORY           = 1,  /* Memory allocation failed. */
+       BDELTA_PATCH_INVALID    = 2,  /* Patch is malformed. */
+       BDELTA_PATCH_MISMATCH   = 3,  /* Patch applied to wrong original string. */
+       
+       /* Internal error codes.  These will never be returned by API functions. */
+       BDELTA_INTERNAL_DMAX_EXCEEDED    = -10,
+       BDELTA_INTERNAL_INPUTS_TOO_LARGE = -11,
+} BDELTAcode;
+
+/*
+ * bdelta_diff - Given two byte strings, generate a "patch" (also a byte string)
+ * that describes how to transform the old string into the new string.
+ *
+ * On success, returns BDELTA_OK, and passes a malloc'd block
+ * and its size through *patch_out and *patch_size_out.
+ *
+ * On failure, returns an error code, and clears *patch_out and *patch_size_out.
+ *
+ * Example:
+ *     const char *old = "abcabba";
+ *     const char *new_ = "cbabac";
+ *     void *patch;
+ *     size_t patch_size;
+ *     BDELTAcode rc;
+ *
+ *     rc = bdelta_diff(old, strlen(old), new_, strlen(new_), &patch, &patch_size);
+ *     if (rc != BDELTA_OK) {
+ *             bdelta_perror("bdelta_diff", rc);
+ *             return;
+ *     }
+ *     ...
+ *     free(patch);
+ */
+BDELTAcode bdelta_diff(
+       const void  *old,       size_t  old_size,
+       const void  *new_,      size_t  new_size,
+       void       **patch_out, size_t *patch_size_out
+);
+
+/*
+ * bdelta_patch - Apply a patch produced by bdelta_diff to the
+ * old string to recover the new string.
+ *
+ * On success, returns BDELTA_OK, and passes a malloc'd block
+ * and its size through *new_out and *new_size_out.
+ *
+ * On failure, returns an error code, and clears *new_out and *new_size_out.
+ *
+ * Example:
+ *     const char *old = "abcabba";
+ *     void *new_;
+ *     size_t new_size;
+ *     BDELTAcode rc;
+ *
+ *     rc = bdelta_patch(old, strlen(old), patch, patch_size, &new_, &new_size);
+ *     if (rc != BDELTA_OK) {
+ *             bdelta_perror("bdelta_patch", rc);
+ *             return;
+ *     }
+ *     fwrite(new_, 1, new_size, stdout);
+ *     putchar('\n');
+ *     free(new_);
+ */
+BDELTAcode bdelta_patch(
+       const void  *old,     size_t  old_size,
+       const void  *patch,   size_t  patch_size,
+       void       **new_out, size_t *new_size_out
+);
+
+/*
+ * bdelta_strerror - Return a string describing a bdelta error code.
+ */
+const char *bdelta_strerror(BDELTAcode code);
+
+/*
+ * bdelta_perror - Print a bdelta error message to stderr.
+ *
+ * This function handles @s the same way perror does.
+ */
+void bdelta_perror(const char *s, BDELTAcode code);
+
+#endif