From: Ezekiel Newren via GitGitGadget Date: Mon, 22 Sep 2025 19:51:29 GMT Subject: [PATCH v4 00/12] Cleanup xdfile_t and xrecord_t in xdiff. Message-ID: In-Reply-To: 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_t xdiff/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 ## 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 ## 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 Signed-off-by: Ezekiel Newren ## 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 ## 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 - ## 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