From 8db3345c2fe5551a7cbc838ddef009813cdeec41 Mon Sep 17 00:00:00 2001
From: Junegunn Choi <junegunn.c@gmail.com>
Date: Sun, 30 Jul 2017 18:15:02 +0900
Subject: [PATCH] Optimize exact match by applying the same trick for fuzzy
match
---
src/algo/algo.go | 62 +++++++++++++++++++++++++++++++++---------------
1 file changed, 43 insertions(+), 19 deletions(-)
diff --git a/src/algo/algo.go b/src/algo/algo.go
index a2f0f2b4..7a6dad32 100644
--- a/src/algo/algo.go
+++ b/src/algo/algo.go
@@ -274,6 +274,41 @@ func trySkip(input *util.Chars, caseSensitive bool, b byte, from int) int {
return from + idx
}
+func isAscii(runes []rune) bool {
+ for _, r := range runes {
+ if r >= utf8.RuneSelf {
+ return false
+ }
+ }
+ return true
+}
+
+func asciiFuzzyIndex(input *util.Chars, pattern []rune, caseSensitive bool) int {
+ // Can't determine
+ if !input.IsBytes() {
+ return 0
+ }
+
+ // Not possible
+ if !isAscii(pattern) {
+ return -1
+ }
+
+ firstIdx, idx := 0, 0
+ for pidx := 0; pidx < len(pattern); pidx++ {
+ idx = trySkip(input, caseSensitive, byte(pattern[pidx]), idx)
+ if idx < 0 {
+ return -1
+ }
+ if pidx == 0 && idx > 0 {
+ // Step back to find the right bonus point
+ firstIdx = idx - 1
+ }
+ idx++
+ }
+ return firstIdx
+}
+
func FuzzyMatchV2(caseSensitive bool, normalize bool, forward bool, input util.Chars, pattern []rune, withPos bool, slab *util.Slab) (Result, *[]int) {
// Assume that pattern is given in lowercase if case-insensitive.
// First check if there's a match and calculate bonus for each position.
@@ -302,30 +337,15 @@ func FuzzyMatchV2(caseSensitive bool, normalize bool, forward bool, input util.C
offset32, T := alloc32(offset32, slab, N, false)
// Phase 1. Optimized search for ASCII string
- firstIdx := 0
- if input.IsBytes() {
- idx := 0
- for pidx := 0; pidx < M; pidx++ {
- // Not possible
- if pattern[pidx] >= utf8.RuneSelf {
- return Result{-1, -1, 0}, nil
- }
- idx = trySkip(&input, caseSensitive, byte(pattern[pidx]), idx)
- if idx < 0 {
- return Result{-1, -1, 0}, nil
- }
- if pidx == 0 && idx > 0 {
- // Step back to find the right bonus point
- firstIdx = idx - 1
- }
- idx++
- }
+ idx := asciiFuzzyIndex(&input, pattern, caseSensitive)
+ if idx < 0 {
+ return Result{-1, -1, 0}, nil
}
// Phase 2. Calculate bonus for each point
pidx, lastIdx, prevClass := 0, 0, charNonWord
input.CopyRunes(T)
- for idx := firstIdx; idx < N; idx++ {
+ for ; idx < N; idx++ {
char := T[idx]
var class charClass
if char <= unicode.MaxASCII {
@@ -657,6 +677,10 @@ func ExactMatchNaive(caseSensitive bool, normalize bool, forward bool, text util
return Result{-1, -1, 0}, nil
}
+ if asciiFuzzyIndex(&text, pattern, caseSensitive) < 0 {
+ return Result{-1, -1, 0}, nil
+ }
+
// For simplicity, only look at the bonus at the first character position
pidx := 0
bestPos, bonus, bestBonus := -1, int16(0), int16(-1)
--
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