X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fjson_escape%2Fjson_escape.c;fp=ccan%2Fjson_escape%2Fjson_escape.c;h=d344940de0a5d934da693b959857326da194fb55;hb=45f9ce170fe09bca014d874ffaa13b900c8285ba;hp=0000000000000000000000000000000000000000;hpb=7623d0829a63e7f95ed6f116b7e9f2f4a023e8e7;p=ccan

diff --git a/ccan/json_escape/json_escape.c b/ccan/json_escape/json_escape.c
new file mode 100644
index 00000000..d344940d
--- /dev/null
+++ b/ccan/json_escape/json_escape.c
@@ -0,0 +1,157 @@
+/* MIT (BSD) license - see LICENSE file for details */
+#include <ccan/json_escape/json_escape.h>
+#include <stdio.h>
+
+struct json_escape *json_escape_string_(const tal_t *ctx,
+					const void *bytes, size_t len)
+{
+	struct json_escape *esc;
+
+	esc = (void *)tal_arr_label(ctx, char, len + 1,
+				    TAL_LABEL(struct json_escape, ""));
+	memcpy(esc->s, bytes, len);
+	esc->s[len] = '\0';
+	return esc;
+}
+
+bool json_escape_eq(const struct json_escape *a, const struct json_escape *b)
+{
+	return streq(a->s, b->s);
+}
+
+static struct json_escape *escape(const tal_t *ctx,
+				  const char *str TAKES,
+				  size_t len,
+				  bool partial)
+{
+	struct json_escape *esc;
+	size_t i, n;
+
+	/* Worst case: all \uXXXX */
+	esc = (struct json_escape *)tal_arr(ctx, char, len * 6 + 1);
+
+	for (i = n = 0; i < len; i++, n++) {
+		char escape = 0;
+		switch (str[i]) {
+		case '\n':
+			escape = 'n';
+			break;
+		case '\b':
+			escape = 'b';
+			break;
+		case '\f':
+			escape = 'f';
+			break;
+		case '\t':
+			escape = 't';
+			break;
+		case '\r':
+			escape = 'r';
+			break;
+		case '\\':
+			if (partial) {
+				/* Don't double-escape standard escapes. */
+				if (str[i+1] == 'n'
+				    || str[i+1] == 'b'
+				    || str[i+1] == 'f'
+				    || str[i+1] == 't'
+				    || str[i+1] == 'r'
+				    || str[i+1] == '/'
+				    || str[i+1] == '\\'
+				    || str[i+1] == '"') {
+					escape = str[i+1];
+					i++;
+					break;
+				}
+				if (str[i+1] == 'u'
+				    && cisxdigit(str[i+2])
+				    && cisxdigit(str[i+3])
+				    && cisxdigit(str[i+4])
+				    && cisxdigit(str[i+5])) {
+					    memcpy(esc->s + n, str + i, 6);
+					    n += 5;
+					    i += 5;
+					    continue;
+				}
+			} /* fall thru */
+		case '"':
+			escape = str[i];
+			break;
+		default:
+			if ((unsigned)str[i] < ' ' || str[i] == 127) {
+				snprintf(esc->s + n, 7, "\\u%04X", str[i]);
+				n += 5;
+				continue;
+			}
+		}
+		if (escape) {
+			esc->s[n++] = '\\';
+			esc->s[n] = escape;
+		} else
+			esc->s[n] = str[i];
+	}
+
+	esc->s[n] = '\0';
+	if (taken(str))
+		tal_free(str);
+	return esc;
+}
+
+struct json_escape *json_partial_escape(const tal_t *ctx, const char *str TAKES)
+{
+	return escape(ctx, str, strlen(str), true);
+}
+
+struct json_escape *json_escape(const tal_t *ctx, const char *str TAKES)
+{
+	return escape(ctx, str, strlen(str), false);
+}
+
+struct json_escape *json_escape_len(const tal_t *ctx, const char *str TAKES,
+				    size_t len)
+{
+	return escape(ctx, str, len, false);
+}
+
+/* By policy, we don't handle \u.  Use UTF-8. */
+const char *json_escape_unescape(const tal_t *ctx, const struct json_escape *esc)
+{
+	char *unesc = tal_arr(ctx, char, strlen(esc->s) + 1);
+	size_t i, n;
+
+	for (i = n = 0; esc->s[i]; i++, n++) {
+		if (esc->s[i] != '\\') {
+			unesc[n] = esc->s[i];
+			continue;
+		}
+
+		i++;
+		switch (esc->s[i]) {
+		case 'n':
+			unesc[n] = '\n';
+			break;
+		case 'b':
+			unesc[n] = '\b';
+			break;
+		case 'f':
+			unesc[n] = '\f';
+			break;
+		case 't':
+			unesc[n] = '\t';
+			break;
+		case 'r':
+			unesc[n] = '\r';
+			break;
+		case '/':
+		case '\\':
+		case '"':
+			unesc[n] = esc->s[i];
+			break;
+		default:
+			return tal_free(unesc);
+		}
+	}
+
+	unesc[n] = '\0';
+	return unesc;
+}