implement converting container/tag identifiers to/from strings

src/misc.c

@@ -0,0 +1,104 @@
+#include "misc.h"
+
+#include <blue/core/endian.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static enum ec3_status identifier_from_int_string(
+	const char *s,
+	uint64_t *out,
+	int base)
+{
+	/* skip leading '0x' */
+	s += 2;
+	char *ep = NULL;
+	uint64_t v = strtoull(s, &ep, base);
+
+	if (!ep || *ep != '\0') {
+		return EC3_ERR_INVALID_VALUE;
+	}
+
+	*out = v;
+	return EC3_SUCCESS;
+}
+
+static bool is_base10_string(const char *s)
+{
+	for (unsigned int i = 0; s[i]; i++) {
+		if (!isdigit(s[i])) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+enum ec3_status ec3_identifier_from_string(const char *s, uint64_t *out)
+{
+	if (s[0] == '0' && s[1] == 'x') {
+		return identifier_from_int_string(s, out, 16);
+	}
+
+	if (is_base10_string(s)) {
+		return identifier_from_int_string(s, out, 10);
+	}
+
+	b_i64 v = {0};
+
+	for (unsigned int i = 0; s[i]; i++) {
+		if (i > sizeof *out) {
+			return EC3_ERR_INVALID_VALUE;
+		}
+
+		v.i_bytes[i] = s[i];
+	}
+
+	*out = b_i64_btoh(v);
+	return EC3_SUCCESS;
+}
+
+enum ec3_status ec3_identifier_to_string(uint64_t id, char *out, size_t max)
+{
+	if (id == 0) {
+		snprintf(out, max, "%016llx", id);
+		return EC3_SUCCESS;
+	}
+
+	bool is_ascii = true;
+	bool zero_only = false;
+
+	b_i64 v = b_i64_htob(id);
+
+	for (unsigned int i = 0; i < sizeof v; i++) {
+		int c = v.i_bytes[i];
+
+		if (c != 0 && zero_only) {
+			is_ascii = false;
+		}
+
+		if (c == 0) {
+			zero_only = true;
+			continue;
+		}
+
+		if (c < 32 || c > 126) {
+			is_ascii = false;
+		}
+	}
+
+	if (is_ascii) {
+		char str[9];
+		memcpy(str, v.i_bytes, sizeof v);
+		str[8] = 0;
+
+		strncpy(out, str, max - 1);
+		out[max - 1] = 0;
+	} else {
+		snprintf(out, max, "%016llx", id);
+	}
+
+	return EC3_SUCCESS;
+}

src/misc.h

@@ -1,12 +1,24 @@
 #ifndef MISC_H_
 #define MISC_H_
 
+#include "status.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
 #ifdef __GNUC__
-#define PACK( __Declaration__ ) __Declaration__ __attribute__((__packed__))
+#define PACK(__Declaration__) __Declaration__ __attribute__((__packed__))
 #endif
 
 #ifdef _MSC_VER
-#define PACK( __Declaration__ ) __pragma( pack(push, 1) ) __Declaration__ __pragma( pack(pop))
+#define PACK(__Declaration__)                                                  \
+	__pragma(pack(push, 1)) __Declaration__ __pragma(pack(pop))
 #endif
 
-#endif
+extern enum ec3_status ec3_identifier_from_string(const char *s, uint64_t *out);
+extern enum ec3_status ec3_identifier_to_string(
+	uint64_t id,
+	char *out,
+	size_t max);
+
+#endif