Add optimization for .."literal"

1 files changed, 16 insertions, 0 deletions

diff --git a/match.c b/match.c
index 1ecee6d..f05089f 100644
--- a/match.c
+++ b/match.c
@@ -446,6 +446,22 @@ static bp_match_t *match(match_ctx_t *ctx, const char *str, bp_pat_t *pat)
             return m;
         }
 
+        // Optimization: for simple cases like `.."foo"` we can speed things up
+        // by skipping ahead to strstr(str, "foo")
+        if (!skip) {
+            bp_pat_t *prereq = get_prerequisite(ctx, target);
+            if (prereq->type == BP_STRING && prereq->min_matchlen > 0) {
+                char *found = ctx->ignorecase ?
+                    strcasestr(str, When(prereq, BP_STRING)->string)
+                    : memmem(str, (size_t)(ctx->end - str), When(prereq, BP_STRING)->string, prereq->min_matchlen);
+                str = found ? found : ctx->end;
+            } else if (prereq->type == BP_END_OF_FILE) {
+                str = ctx->end;
+            } else if (prereq->type == BP_END_OF_LINE) {
+                str += strcspn(str, "\n\r");
+            }
+        }
+
         size_t child_cap = 0, nchildren = 0;
         for (const char *prev = NULL; prev < str; ) {
             prev = str;