[PATCH v4 00/12] Cleanup xdfile_t and xrecord_t in xdiff.
- From
Ezekiel Newren via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Sep 22, 2025, 19:51 UTC
- Message-ID
- <pull.2048.v4.git.git.1758570701.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.2048.v3.git.git.1758294992.gitgitgadget@gmail.com>
Changes since v3.
* Address review feedback. * Split the deletion of xdl_get_rec() into 2 commits. * Move NO, YES, MAYBE into xprepare.c, and use bool literals. * refactor 'char rchg' to 'bool changed'
Changes since v2.
* No patch changes, just resending to get patch 9 to show up on the mailing list. * A few tweaks to the cover letter.
Changes since v1, to address review feedback.
* Only include the clean up patches; The remaining patches will be split into a separate series. * Commit message clarifications. * Minor style cleanups. * Performance impacts included in commit message of patch 8.
Relevant part of the original cover letter follows: ===================================================
Before:
typedef struct s_xrecord {
struct s_xrecord *next;
char const *ptr;
long size;
unsigned long ha;
} xrecord_t;typedef struct s_xdfile {
chastore_t rcha;
long nrec;
unsigned int hbits;
xrecord_t **rhash;
long dstart, dend;
xrecord_t **recs;
char *rchg;
long *rindex;
long nreff;
unsigned long *ha;
} xdfile_t;After cleanup:
typedef struct s_xrecord {
char const *ptr;
long size;
unsigned long ha;
} xrecord_t;typedef struct s_xdfile {
xrecord_t *recs;
long nrec;
long dstart, dend;
char *rchg;
long *rindex;
long nreff;
} xdfile_t;===
Ezekiel Newren (12):
xdiff: delete static forward declarations in xprepare
xdiff: delete local variables and initialize/free xdfile_t directly
xdiff: delete unnecessary fields from xrecord_t and xdfile_t
xdiff: delete superfluous function xdl_get_rec() in xemit
xdiff: delete superfluous local variables that alias fields in
xrecord_t
xdiff: delete struct diffdata_t
xdiff: delete redundant array xdfile_t.ha
xdiff: delete fields ha, line, size in xdlclass_t in favor of an
xrecord_t
xdiff: delete chastore from xdfile_t
xdiff: delete rchg aliasing
xdiff: use bool literals for xdfile_t.rchg
xdiff: refactor 'char *rchg' to 'bool *changed' in xdfile_txdiff/xdiffi.c | 101 ++++++++--------- xdiff/xdiffi.h | 11 +- xdiff/xemit.c | 38 +++---- xdiff/xhistogram.c | 10 +- xdiff/xmerge.c | 56 +++++----- xdiff/xpatience.c | 18 ++-- xdiff/xprepare.c | 263 +++++++++++++++++---------------------------- xdiff/xtypes.h | 9 +- xdiff/xutils.c | 16 +-- 9 files changed, 212 insertions(+), 310 deletions(-)
base-commit: c44beea485f0f2feaf460e2ac87fdd5608d63cf0 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2048%2Fezekielnewren%2Fuse_rust_types_in_xdiff-v4 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2048/ezekielnewren/use_rust_types_in_xdiff-v4 Pull-Request: https://github.com/git/git/pull/2048
Range-diff vs v3:
1: 784cffcef5 ! 1: 79d1099656 xdiff: delete static forward declarations in xprepare
@@ xdiff/xprepare.c: static int xdl_optimize_ctxs(xdlclassifier_t *cf, xdfile_t *xd
+ xdl_free_ctx(&xe->xdf1);
+ xdl_free_classifier(&cf);
+ return -1;
-+ }
++ }
+
+ xdl_free_classifier(&cf);
+
2: b79157e64f = 2: 9142f28fcd xdiff: delete local variables and initialize/free xdfile_t directly
3: 2e8de5be03 = 3: 13f00f5683 xdiff: delete unnecessary fields from xrecord_t and xdfile_t
-: ---------- > 4: 311279c123 xdiff: delete superfluous function xdl_get_rec() in xemit
4: ddfee67e06 ! 5: d84658ac83 xdiff: delete xdl_get_rec() in xemit
@@ Metadata
Author: Ezekiel Newren <ezekielnewren@gmail.com>
## Commit message ##
- xdiff: delete xdl_get_rec() in xemit
+ xdiff: delete superfluous local variables that alias fields in xrecord_t
- This function aliases the fields of xrecord_t, which makes it harder
- to track the usages of those fields. Delete it.
+ Use the type xrecord_t as the local variable for the functions in the
+ file xdiff/xemit.c.
Signed-off-by: Ezekiel Newren <ezekielnewren@gmail.com>
## xdiff/xemit.c ##
@@
-
#include "xinclude.h"
--static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
--
-- *rec = xdf->recs[ri]->ptr;
--
-- return xdf->recs[ri]->size;
--}
--
--
+
-static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
- long size, psize = strlen(pre);
-- char const *rec;
--
-- size = xdl_get_rec(xdf, ri, &rec);
-- if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
+- char const *rec = xdf->recs[ri]->ptr;
+static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb)
+{
+ xrecord_t *rec = xdf->recs[ri];
-+ if (xdl_emit_diffrec(rec->ptr, rec->size, pre, strlen(pre), ecb) < 0) {
+- size = xdf->recs[ri]->size;
+- if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0)
++ if (xdl_emit_diffrec(rec->ptr, rec->size, pre, strlen(pre), ecb) < 0)
return -1;
- }
+ return 0;
@@ xdiff/xemit.c: static long def_ff(const char *rec, long len, char *buf, long sz)
static long match_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri,
char *buf, long sz)
{
-- const char *rec;
-- long len = xdl_get_rec(xdf, ri, &rec);
+- const char *rec = xdf->recs[ri]->ptr;
+- long len = xdf->recs[ri]->size;
+ xrecord_t *rec = xdf->recs[ri];
+
if (!xecfg->find_func)
@@ xdiff/xemit.c: static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg
static int is_empty_rec(xdfile_t *xdf, long ri)
{
-- const char *rec;
-- long len = xdl_get_rec(xdf, ri, &rec);
+- const char *rec = xdf->recs[ri]->ptr;
+- long len = xdf->recs[ri]->size;
+ xrecord_t *rec = xdf->recs[ri];
+ long i = 0;
5: 807ce3e5aa = 6: bf16453846 xdiff: delete struct diffdata_t
6: 0bacb1191d ! 7: 4ef7f243e9 xdiff: delete redundant array xdfile_t.ha
@@ Commit message
This makes the code about 5% slower. The fields rindex and ha are
specific to the classic diff (myers and minimal). I plan on creating a
- struct for classic diff, but there'a alot of cleanup that needs to be
+ struct for classic diff, but there's a lot of cleanup that needs to be
done before that can happen and leaving ha in would make those cleanups
harder to follow.
7: e1e94107c9 ! 8: 3b6c2127c4 xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t
@@ Commit message
xdlclass_t.size -> xrecord_t.size
xdlclass_t.ha -> xrecord_t.ha
- Remove aliasing from xdlclass_t, to reduce future refactoring mistakes.
+ xdlclass_t carries a copy of the data in xrecord_t, but instead of
+ embedding xrecord_t it duplicates the individual fields. A future
+ commit will change the types used in xrecord_t so embed it in
+ xdlclass_t first, so we don't have to remember to change the types
+ here as well.
Best-viewed-with: --color-words
+ Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Ezekiel Newren <ezekielnewren@gmail.com>
## xdiff/xprepare.c ##
@@ xdiff/xprepare.c: static int xdl_classify_record(unsigned int pass, xdlclassifie
- rcrec->line = line;
- rcrec->size = rec->size;
- rcrec->ha = rec->ha;
-+ rcrec->rec.ptr = rec->ptr;
-+ rcrec->rec.size = rec->size;
-+ rcrec->rec.ha = rec->ha;
++ rcrec->rec = *rec;
rcrec->len1 = rcrec->len2 = 0;
rcrec->next = cf->rchash[hi];
cf->rchash[hi] = rcrec;
8: fae26d2a04 ! 9: f7b5021e48 xdiff: delete chastore from xdfile_t
@@ xdiff/xemit.c
- xrecord_t *rec = xdf->recs[ri];
+ xrecord_t *rec = &xdf->recs[ri];
- if (xdl_emit_diffrec(rec->ptr, rec->size, pre, strlen(pre), ecb) < 0) {
+ if (xdl_emit_diffrec(rec->ptr, rec->size, pre, strlen(pre), ecb) < 0)
return -1;
@@ xdiff/xemit.c: static long def_ff(const char *rec, long len, char *buf, long sz)
static long match_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri,
9: fd54135560 = 10: 97135495e2 xdiff: delete rchg aliasing
10: 1e404c3290 ! 11: b544c15a67 xdiff: treat xdfile_t.rchg like an enum
@@ Metadata
Author: Ezekiel Newren <ezekielnewren@gmail.com>
## Commit message ##
- xdiff: treat xdfile_t.rchg like an enum
+ xdiff: use bool literals for xdfile_t.rchg
- Define macros NO(0), YES(1), MAYBE(2) as the enum values for rchg to
- make the code easier to follow. Perhaps 'rchg' should be renamed to
- 'changed'?
-
- A few of the code changes might appear to change behavior, such as:
- - while (xdf->rchg[g->start - 1])
- + while (xdf->rchg[g->start - 1] == YES)
- because it appears the value of MAYBE is being ignored. However, MAYBE
- is only ever assigned as a value to a temporary array (dis1 & dis2) and
- then as a last step use that temporary array to decide if it wants to
- change xdfile_t.rchg[i] to YES or leave it as NO. As such, rchg will
- never have a value of MAYBE and thus there is no behavioral change.
+ Define macros NO(0), YES(1), MAYBE(2) as the enum values for dis1 and
+ dis2 to make the code easier to follow.
Best-viewed-with: --color-words
Signed-off-by: Ezekiel Newren <ezekielnewren@gmail.com>
- ## xdiff/xdiff.h ##
-@@
- extern "C" {
- #endif /* #ifdef __cplusplus */
-
-+#define NO 0
-+#define YES 1
-+#define MAYBE 2
-+
- /* xpparm_t.flags */
- #define XDF_NEED_MINIMAL (1 << 0)
-
-
## xdiff/xdiffi.c ##
@@ xdiff/xdiffi.c: int xdl_recs_cmp(xdfile_t *xdf1, long off1, long lim1,
*/
if (off1 == lim1) {
for (; off2 < lim2; off2++)
- xdf2->rchg[xdf2->rindex[off2]] = 1;
-+ xdf2->rchg[xdf2->rindex[off2]] = YES;
++ xdf2->rchg[xdf2->rindex[off2]] = true;
} else if (off2 == lim2) {
for (; off1 < lim1; off1++)
- xdf1->rchg[xdf1->rindex[off1]] = 1;
-+ xdf1->rchg[xdf1->rindex[off1]] = YES;
++ xdf1->rchg[xdf1->rindex[off1]] = true;
} else {
xdpsplit_t spl;
spl.i1 = spl.i2 = 0;
-@@ xdiff/xdiffi.c: struct xdlgroup {
- static void group_init(xdfile_t *xdf, struct xdlgroup *g)
- {
- g->start = g->end = 0;
-- while (xdf->rchg[g->end])
-+ while (xdf->rchg[g->end] == YES)
- g->end++;
- }
-
-@@ xdiff/xdiffi.c: static inline int group_next(xdfile_t *xdf, struct xdlgroup *g)
- return -1;
-
- g->start = g->end + 1;
-- for (g->end = g->start; xdf->rchg[g->end]; g->end++)
-+ for (g->end = g->start; xdf->rchg[g->end] == YES; g->end++)
- ;
-
- return 0;
-@@ xdiff/xdiffi.c: static inline int group_previous(xdfile_t *xdf, struct xdlgroup *g)
- return -1;
-
- g->end = g->start - 1;
-- for (g->start = g->end; xdf->rchg[g->start - 1]; g->start--)
-+ for (g->start = g->end; xdf->rchg[g->start - 1] == YES; g->start--)
- ;
-
- return 0;
@@ xdiff/xdiffi.c: static int group_slide_down(xdfile_t *xdf, struct xdlgroup *g)
{
if (g->end < xdf->nrec &&
recs_match(&xdf->recs[g->start], &xdf->recs[g->end])) {
- xdf->rchg[g->start++] = 0;
- xdf->rchg[g->end++] = 1;
-+ xdf->rchg[g->start++] = NO;
-+ xdf->rchg[g->end++] = YES;
++ xdf->rchg[g->start++] = false;
++ xdf->rchg[g->end++] = true;
-- while (xdf->rchg[g->end])
-+ while (xdf->rchg[g->end] == YES)
+ while (xdf->rchg[g->end])
g->end++;
-
- return 0;
@@ xdiff/xdiffi.c: static int group_slide_up(xdfile_t *xdf, struct xdlgroup *g)
{
if (g->start > 0 &&
recs_match(&xdf->recs[g->start - 1], &xdf->recs[g->end - 1])) {
- xdf->rchg[--g->start] = 1;
- xdf->rchg[--g->end] = 0;
-+ xdf->rchg[--g->start] = YES;
-+ xdf->rchg[--g->end] = NO;
++ xdf->rchg[--g->start] = true;
++ xdf->rchg[--g->end] = false;
-- while (xdf->rchg[g->start - 1])
-+ while (xdf->rchg[g->start - 1] == YES)
+ while (xdf->rchg[g->start - 1])
g->start--;
-
- return 0;
## xdiff/xhistogram.c ##
@@ xdiff/xhistogram.c: redo:
@@ xdiff/xhistogram.c: redo:
if (!count1) {
while(count2--)
- env->xdf2.rchg[line2++ - 1] = 1;
-+ env->xdf2.rchg[line2++ - 1] = YES;
++ env->xdf2.rchg[line2++ - 1] = true;
return 0;
} else if (!count2) {
while(count1--)
- env->xdf1.rchg[line1++ - 1] = 1;
-+ env->xdf1.rchg[line1++ - 1] = YES;
++ env->xdf1.rchg[line1++ - 1] = true;
return 0;
}
@@ xdiff/xhistogram.c: redo:
if (lcs.begin1 == 0 && lcs.begin2 == 0) {
while (count1--)
- env->xdf1.rchg[line1++ - 1] = 1;
-+ env->xdf1.rchg[line1++ - 1] = YES;
++ env->xdf1.rchg[line1++ - 1] = true;
while (count2--)
- env->xdf2.rchg[line2++ - 1] = 1;
-+ env->xdf2.rchg[line2++ - 1] = YES;
++ env->xdf2.rchg[line2++ - 1] = true;
result = 0;
} else {
result = histogram_diff(xpp, env,
@@ xdiff/xpatience.c: static int patience_diff(xpparam_t const *xpp, xdfenv_t *env,
if (!count1) {
while(count2--)
- env->xdf2.rchg[line2++ - 1] = 1;
-+ env->xdf2.rchg[line2++ - 1] = YES;
++ env->xdf2.rchg[line2++ - 1] = true;
return 0;
} else if (!count2) {
while(count1--)
- env->xdf1.rchg[line1++ - 1] = 1;
-+ env->xdf1.rchg[line1++ - 1] = YES;
++ env->xdf1.rchg[line1++ - 1] = true;
return 0;
}
@@ xdiff/xpatience.c: static int patience_diff(xpparam_t const *xpp, xdfenv_t *env,
if (!map.has_matches) {
while(count1--)
- env->xdf1.rchg[line1++ - 1] = 1;
-+ env->xdf1.rchg[line1++ - 1] = YES;
++ env->xdf1.rchg[line1++ - 1] = true;
while(count2--)
- env->xdf2.rchg[line2++ - 1] = 1;
-+ env->xdf2.rchg[line2++ - 1] = YES;
++ env->xdf2.rchg[line2++ - 1] = true;
xdl_free(map.entries);
return 0;
}
## xdiff/xprepare.c ##
+@@
+ #define XDL_GUESS_NLINES1 256
+ #define XDL_GUESS_NLINES2 20
+
++#define NO 0
++#define YES 1
++#define MAYBE 2
+
+ typedef struct s_xdlclass {
+ struct s_xdlclass *next;
@@ xdiff/xprepare.c: static int xdl_clean_mmatch(char const *dis, long i, long s, long e) {
* current line (i) is already a multimatch line.
*/
@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *
xdf1->rindex[nreff++] = i;
} else
- xdf1->rchg[i] = 1;
-+ xdf1->rchg[i] = YES;
++ xdf1->rchg[i] = true;
}
xdf1->nreff = nreff;
@@ xdiff/xprepare.c: static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *
xdf2->rindex[nreff++] = i;
} else
- xdf2->rchg[i] = 1;
-+ xdf2->rchg[i] = YES;
++ xdf2->rchg[i] = true;
}
xdf2->nreff = nreff;
-: ---------- > 12: 034a4a7b2a xdiff: refactor 'char *rchg' to 'bool *changed' in xdfile_t-- gitgitgadget