c: move c files into nostrdb in prep for switchover

nostrdb/hex.h

@@ -0,0 +1,84 @@
+/* CC0 (Public domain) - see LICENSE file for details */
+#ifndef CCAN_HEX_H
+#define CCAN_HEX_H
+#include "config.h"
+#include <stdbool.h>
+#include <stdlib.h>
+
+/**
+ * hex_decode - Unpack a hex string.
+ * @str: the hexadecimal string
+ * @slen: the length of @str
+ * @buf: the buffer to write the data into
+ * @bufsize: the length of
+ *
+ * Returns false if there are any characters which aren't 0-9, a-f or A-F,
+ * of the string wasn't the right length for @bufsize.
+ *
+ * Example:
+ *    unsigned char data[20];
+ *
+ *    if (!hex_decode(argv[1], strlen(argv[1]), data, 20))
+ *        printf("String is malformed!\n");
+ */
+bool hex_decode(const char *str, size_t slen, void *buf, size_t bufsize);
+
+/**
+ * hex_encode - Create a nul-terminated hex string
+ * @buf: the buffer to read the data from
+ * @bufsize: the length of buf
+ * @dest: the string to fill
+ * @destsize: the max size of the string
+ *
+ * Returns true if the string, including terminator, fit in @destsize;
+ *
+ * Example:
+ *    unsigned char buf[] = { 0x1F, 0x2F };
+ *    char str[5];
+ *
+ *    if (!hex_encode(buf, sizeof(buf), str, sizeof(str)))
+ *        abort();
+ */
+bool hex_encode(const void *buf, size_t bufsize, char *dest, size_t destsize);
+
+/**
+ * hex_str_size - Calculate how big a nul-terminated hex string is
+ * @bytes: bytes of data to represent
+ *
+ * Example:
+ *    unsigned char buf[] = { 0x1F, 0x2F };
+ *    char str[hex_str_size(sizeof(buf))];
+ *
+ *    hex_encode(buf, sizeof(buf), str, sizeof(str));
+ */
+static inline size_t hex_str_size(size_t bytes)
+{
+    return 2 * bytes + 1;
+}
+
+/**
+ * hex_data_size - Calculate how many bytes of data in a hex string
+ * @strlen: the length of the string (with or without NUL)
+ *
+ * Example:
+ *    const char str[] = "1F2F";
+ *    unsigned char buf[hex_data_size(sizeof(str))];
+ *
+ *    hex_decode(str, strlen(str), buf, sizeof(buf));
+ */
+static inline size_t hex_data_size(size_t strlen)
+{
+    return strlen / 2;
+}
+
+static inline char hexchar(unsigned int val)
+{
+    if (val < 10)
+        return '0' + val;
+    if (val < 16)
+        return 'a' + val - 10;
+    abort();
+}
+
+
+#endif /* CCAN_HEX_H */