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authorVincent Ambo <mail@tazj.in>2021-09-21T10·03+0300
committerVincent Ambo <mail@tazj.in>2021-09-21T11·29+0300
commit43b1791ec601732ac31195df96781a848360a9ac (patch)
treedaae8d638343295d2f1f7da955e556ef4c958864 /third_party/git/levenshtein.c
parent2d8e7dc9d9c38127ec4ebd13aee8e8f586a43318 (diff)
chore(3p/git): Unvendor git and track patches instead r/2903
This was vendored a long time ago under the expectation that keeping
it in sync with cgit would be easier this way, but it has proven not
to be a big issue.

On the other hand, a vendored copy of git is an annoying maintenance
burden. It is much easier to rebase the single (dottime) patch that we
have.

This removes the vendored copy of git and instead passes the git
source code to cgit via `pkgs.srcOnly`, which includes the applied
patch so that cgit can continue rendering dottime.

Change-Id: If31f62dea7ce688fd1b9050204e9378019775f2b
Diffstat (limited to 'third_party/git/levenshtein.c')
-rw-r--r--third_party/git/levenshtein.c86
1 files changed, 0 insertions, 86 deletions
diff --git a/third_party/git/levenshtein.c b/third_party/git/levenshtein.c
deleted file mode 100644
index d2632690d510..000000000000
--- a/third_party/git/levenshtein.c
+++ /dev/null
@@ -1,86 +0,0 @@
-#include "cache.h"
-#include "levenshtein.h"
-
-/*
- * This function implements the Damerau-Levenshtein algorithm to
- * calculate a distance between strings.
- *
- * Basically, it says how many letters need to be swapped, substituted,
- * deleted from, or added to string1, at least, to get string2.
- *
- * The idea is to build a distance matrix for the substrings of both
- * strings.  To avoid a large space complexity, only the last three rows
- * are kept in memory (if swaps had the same or higher cost as one deletion
- * plus one insertion, only two rows would be needed).
- *
- * At any stage, "i + 1" denotes the length of the current substring of
- * string1 that the distance is calculated for.
- *
- * row2 holds the current row, row1 the previous row (i.e. for the substring
- * of string1 of length "i"), and row0 the row before that.
- *
- * In other words, at the start of the big loop, row2[j + 1] contains the
- * Damerau-Levenshtein distance between the substring of string1 of length
- * "i" and the substring of string2 of length "j + 1".
- *
- * All the big loop does is determine the partial minimum-cost paths.
- *
- * It does so by calculating the costs of the path ending in characters
- * i (in string1) and j (in string2), respectively, given that the last
- * operation is a substitution, a swap, a deletion, or an insertion.
- *
- * This implementation allows the costs to be weighted:
- *
- * - w (as in "sWap")
- * - s (as in "Substitution")
- * - a (for insertion, AKA "Add")
- * - d (as in "Deletion")
- *
- * Note that this algorithm calculates a distance _iff_ d == a.
- */
-int levenshtein(const char *string1, const char *string2,
-		int w, int s, int a, int d)
-{
-	int len1 = strlen(string1), len2 = strlen(string2);
-	int *row0, *row1, *row2;
-	int i, j;
-
-	ALLOC_ARRAY(row0, len2 + 1);
-	ALLOC_ARRAY(row1, len2 + 1);
-	ALLOC_ARRAY(row2, len2 + 1);
-
-	for (j = 0; j <= len2; j++)
-		row1[j] = j * a;
-	for (i = 0; i < len1; i++) {
-		int *dummy;
-
-		row2[0] = (i + 1) * d;
-		for (j = 0; j < len2; j++) {
-			/* substitution */
-			row2[j + 1] = row1[j] + s * (string1[i] != string2[j]);
-			/* swap */
-			if (i > 0 && j > 0 && string1[i - 1] == string2[j] &&
-					string1[i] == string2[j - 1] &&
-					row2[j + 1] > row0[j - 1] + w)
-				row2[j + 1] = row0[j - 1] + w;
-			/* deletion */
-			if (row2[j + 1] > row1[j + 1] + d)
-				row2[j + 1] = row1[j + 1] + d;
-			/* insertion */
-			if (row2[j + 1] > row2[j] + a)
-				row2[j + 1] = row2[j] + a;
-		}
-
-		dummy = row0;
-		row0 = row1;
-		row1 = row2;
-		row2 = dummy;
-	}
-
-	i = row1[len2];
-	free(row0);
-	free(row1);
-	free(row2);
-
-	return i;
-}