internal/lsp/diff: remove redundant memory allocate and copy operations in function 'shortestEditSequence'.
These redundant operations can cause more memory and cpu consumption.
Change-Id: I54e0e23a8d1079c7991f55c897c441566c5fb2d8
GitHub-Last-Rev: 13162aa1e88ff272738c6a6675010edd2140c8a4
GitHub-Pull-Request: golang/tools#120
Reviewed-on: https://go-review.googlesource.com/c/tools/+/182478
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/internal/lsp/diff/diff.go b/internal/lsp/diff/diff.go
index f894b86..a789a7f 100644
--- a/internal/lsp/diff/diff.go
+++ b/internal/lsp/diff/diff.go
@@ -174,6 +174,7 @@
// Iterate through the maximum possible length of the SES (N+M).
for d := 0; d <= N+M; d++ {
+ copyV := make([]int, len(V))
// k lines are represented by the equation y = x - k. We move in
// increments of 2 because end points for even d are on even k lines.
for k := -d; k <= d; k += 2 {
@@ -197,16 +198,19 @@
V[k+offset] = x
- // Save the state of the array.
- copyV := make([]int, len(V))
- copy(copyV, V)
- trace[d] = copyV
-
// Return if we've exceeded the maximum values.
if x == M && y == N {
+ // Save the state of the array, and exit function
+ copy(copyV, V)
+ trace[d] = copyV
+
return trace, offset
}
}
+
+ // Save the state of the array, and continue loop
+ copy(copyV, V)
+ trace[d] = copyV
}
return nil, 0
}
