--- a/src/ucx/string.c Tue Aug 25 12:07:56 2020 +0200
+++ b/src/ucx/string.c Sat Oct 24 17:34:32 2020 +0200
@@ -662,6 +662,136 @@
return ret;
}
+#define REPLACE_INDEX_BUFFER_MAX 100
+
+struct scstrreplace_ibuf {
+ size_t* buf;
+ unsigned int len; /* small indices */
+ struct scstrreplace_ibuf* next;
+};
+
+static void scstrrepl_free_ibuf(struct scstrreplace_ibuf *buf) {
+ while (buf) {
+ struct scstrreplace_ibuf *next = buf->next;
+ free(buf->buf);
+ free(buf);
+ buf = next;
+ }
+}
+
+sstr_t scstrreplacen_a(UcxAllocator *allocator, scstr_t str,
+ scstr_t pattern, scstr_t replacement, size_t replmax) {
+
+ if (pattern.length == 0 || pattern.length > str.length || replmax == 0)
+ return sstrdup(str);
+
+ /* Compute expected buffer length */
+ size_t ibufmax = str.length / pattern.length;
+ size_t ibuflen = replmax < ibufmax ? replmax : ibufmax;
+ if (ibuflen > REPLACE_INDEX_BUFFER_MAX) {
+ ibuflen = REPLACE_INDEX_BUFFER_MAX;
+ }
+
+ /* Allocate first index buffer */
+ struct scstrreplace_ibuf *firstbuf, *curbuf;
+ firstbuf = curbuf = calloc(1, sizeof(struct scstrreplace_ibuf));
+ if (!firstbuf) return sstrn(NULL, 0);
+ firstbuf->buf = calloc(ibuflen, sizeof(size_t));
+ if (!firstbuf->buf) {
+ free(firstbuf);
+ return sstrn(NULL, 0);
+ }
+
+ /* Search occurrences */
+ scstr_t searchstr = str;
+ size_t found = 0;
+ do {
+ scstr_t match = scstrscstr(searchstr, pattern);
+ if (match.length > 0) {
+ /* Allocate next buffer in chain, if required */
+ if (curbuf->len == ibuflen) {
+ struct scstrreplace_ibuf *nextbuf =
+ calloc(1, sizeof(struct scstrreplace_ibuf));
+ if (!nextbuf) {
+ scstrrepl_free_ibuf(firstbuf);
+ return sstrn(NULL, 0);
+ }
+ nextbuf->buf = calloc(ibuflen, sizeof(size_t));
+ if (!nextbuf->buf) {
+ free(nextbuf);
+ scstrrepl_free_ibuf(firstbuf);
+ return sstrn(NULL, 0);
+ }
+ curbuf->next = nextbuf;
+ curbuf = nextbuf;
+ }
+
+ /* Record match index */
+ found++;
+ size_t idx = match.ptr - str.ptr;
+ curbuf->buf[curbuf->len++] = idx;
+ searchstr.ptr = match.ptr + pattern.length;
+ searchstr.length = str.length - idx - pattern.length;
+ } else {
+ break;
+ }
+ } while (searchstr.length > 0 && found < replmax);
+
+ /* Allocate result string */
+ sstr_t result;
+ {
+ ssize_t adjlen = (ssize_t) replacement.length - (ssize_t) pattern.length;
+ size_t rcount = 0;
+ curbuf = firstbuf;
+ do {
+ rcount += curbuf->len;
+ curbuf = curbuf->next;
+ } while (curbuf);
+ result.length = str.length + rcount * adjlen;
+ result.ptr = almalloc(allocator, result.length);
+ if (!result.ptr) {
+ scstrrepl_free_ibuf(firstbuf);
+ return sstrn(NULL, 0);
+ }
+ }
+
+ /* Build result string */
+ curbuf = firstbuf;
+ size_t srcidx = 0;
+ char* destptr = result.ptr;
+ do {
+ for (size_t i = 0; i < curbuf->len; i++) {
+ /* Copy source part up to next match*/
+ size_t idx = curbuf->buf[i];
+ size_t srclen = idx - srcidx;
+ if (srclen > 0) {
+ memcpy(destptr, str.ptr+srcidx, srclen);
+ destptr += srclen;
+ srcidx += srclen;
+ }
+
+ /* Copy the replacement and skip the source pattern */
+ srcidx += pattern.length;
+ memcpy(destptr, replacement.ptr, replacement.length);
+ destptr += replacement.length;
+ }
+ curbuf = curbuf->next;
+ } while (curbuf);
+ memcpy(destptr, str.ptr+srcidx, str.length-srcidx);
+
+ /* Free index buffer */
+ scstrrepl_free_ibuf(firstbuf);
+
+ return result;
+}
+
+sstr_t scstrreplacen(scstr_t str, scstr_t pattern,
+ scstr_t replacement, size_t replmax) {
+ return scstrreplacen_a(ucx_default_allocator(),
+ str, pattern, replacement, replmax);
+}
+
+
// type adjustment functions
scstr_t ucx_sc2sc(scstr_t str) {
return str;