Re: [PATCH 07/10] xdiff: replace xdfile_t.dstart with xdfenv_t.delta_start
From: Phillip Wood <hidden>
Date: 2026-01-20 16:32:56
On 02/01/2026 18:52, Ezekiel Newren via GitGitGadget wrote:
From: Ezekiel Newren <redacted> Placing delta_start in xdfenv_t instead of xdfile_t provides a more appropriate context since this variable only makes sense with a pair of files. View with --color-words.
So as dstart and dend must be the same for both files we now store the values once in xdfenv_t. That explains why we start passing xdfenv_t around rather than xdfile_t in patch 5. Thanks Phillip
quoted hunk ↗ jump to hunk
Signed-off-by: Ezekiel Newren <redacted> --- xdiff/xhistogram.c | 4 ++-- xdiff/xpatience.c | 4 ++-- xdiff/xprepare.c | 17 +++++++++-------- xdiff/xtypes.h | 3 ++- 4 files changed, 15 insertions(+), 13 deletions(-)diff --git a/xdiff/xhistogram.c b/xdiff/xhistogram.c index 5ae1282c27..eb6a52d9ba 100644 --- a/xdiff/xhistogram.c +++ b/xdiff/xhistogram.c@@ -365,6 +365,6 @@ out: int xdl_do_histogram_diff(xpparam_t const *xpp, xdfenv_t *env) { return histogram_diff(xpp, env, - env->xdf1.dstart + 1, env->xdf1.dend - env->xdf1.dstart + 1, - env->xdf2.dstart + 1, env->xdf2.dend - env->xdf2.dstart + 1); + env->delta_start + 1, env->xdf1.dend - env->delta_start + 1, + env->delta_start + 1, env->xdf2.dend - env->delta_start + 1); }diff --git a/xdiff/xpatience.c b/xdiff/xpatience.c index 2bce07cf48..bd0ffbb417 100644 --- a/xdiff/xpatience.c +++ b/xdiff/xpatience.c@@ -374,6 +374,6 @@ static int patience_diff(xpparam_t const *xpp, xdfenv_t *env, int xdl_do_patience_diff(xpparam_t const *xpp, xdfenv_t *env) { return patience_diff(xpp, env, - env->xdf1.dstart + 1, env->xdf1.dend - env->xdf1.dstart + 1, - env->xdf2.dstart + 1, env->xdf2.dend - env->xdf2.dstart + 1); + env->delta_start + 1, env->xdf1.dend - env->delta_start + 1, + env->delta_start + 1, env->xdf2.dend - env->delta_start + 1); }diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c index 06b6a6f804..e88468e74c 100644 --- a/xdiff/xprepare.c +++ b/xdiff/xprepare.c@@ -173,7 +173,6 @@ static int xdl_prepare_ctx(mmfile_t *mf, xdfile_t *xdf, uint64_t flags) { xdf->changed += 1; xdf->nreff = 0; - xdf->dstart = 0; xdf->dend = xdf->nrec - 1; return 0;@@ -287,7 +286,7 @@ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfenv_t *xe) { */ if ((mlim = xdl_bogosqrt((long)xe->xdf1.nrec)) > XDL_MAX_EQLIMIT) mlim = XDL_MAX_EQLIMIT; - for (i = xe->xdf1.dstart, recs = &xe->xdf1.recs[xe->xdf1.dstart]; i <= xe->xdf1.dend; i++, recs++) { + for (i = xe->delta_start, recs = &xe->xdf1.recs[xe->delta_start]; i <= xe->xdf1.dend; i++, recs++) { rcrec = cf->rcrecs[recs->minimal_perfect_hash]; nm = rcrec ? rcrec->len2 : 0; action1[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;@@ -295,7 +294,7 @@ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfenv_t *xe) { if ((mlim = xdl_bogosqrt((long)xe->xdf2.nrec)) > XDL_MAX_EQLIMIT) mlim = XDL_MAX_EQLIMIT; - for (i = xe->xdf2.dstart, recs = &xe->xdf2.recs[xe->xdf2.dstart]; i <= xe->xdf2.dend; i++, recs++) { + for (i = xe->delta_start, recs = &xe->xdf2.recs[xe->delta_start]; i <= xe->xdf2.dend; i++, recs++) { rcrec = cf->rcrecs[recs->minimal_perfect_hash]; nm = rcrec ? rcrec->len1 : 0; action2[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;@@ -306,10 +305,10 @@ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfenv_t *xe) { * false, or become true. */ xe->xdf1.nreff = 0; - for (i = xe->xdf1.dstart, recs = &xe->xdf1.recs[xe->xdf1.dstart]; + for (i = xe->delta_start, recs = &xe->xdf1.recs[xe->delta_start]; i <= xe->xdf1.dend; i++, recs++) { if (action1[i] == KEEP || - (action1[i] == INVESTIGATE && !xdl_clean_mmatch(action1, i, xe->xdf1.dstart, xe->xdf1.dend))) { + (action1[i] == INVESTIGATE && !xdl_clean_mmatch(action1, i, xe->delta_start, xe->xdf1.dend))) { xe->xdf1.reference_index[xe->xdf1.nreff++] = i; /* changed[i] remains false, i.e. keep */ } else@@ -318,10 +317,10 @@ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfenv_t *xe) { } xe->xdf2.nreff = 0; - for (i = xe->xdf2.dstart, recs = &xe->xdf2.recs[xe->xdf2.dstart]; + for (i = xe->delta_start, recs = &xe->xdf2.recs[xe->delta_start]; i <= xe->xdf2.dend; i++, recs++) { if (action2[i] == KEEP || - (action2[i] == INVESTIGATE && !xdl_clean_mmatch(action2, i, xe->xdf2.dstart, xe->xdf2.dend))) { + (action2[i] == INVESTIGATE && !xdl_clean_mmatch(action2, i, xe->delta_start, xe->xdf2.dend))) { xe->xdf2.reference_index[xe->xdf2.nreff++] = i; /* changed[i] remains false, i.e. keep */ } else@@ -348,7 +347,7 @@ static void xdl_trim_ends(xdfenv_t *xe) size_t mph1 = xe->xdf1.recs[i].minimal_perfect_hash; size_t mph2 = xe->xdf2.recs[i].minimal_perfect_hash; if (mph1 != mph2) { - xe->xdf1.dstart = xe->xdf2.dstart = (ssize_t)i; + xe->delta_start = (ssize_t)i; lim -= i; break; }@@ -370,6 +369,8 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdfenv_t *xe) { xdlclassifier_t cf; + xe->delta_start = 0; + if (xdl_prepare_ctx(mf1, &xe->xdf1, xpp->flags) < 0) { return -1;diff --git a/xdiff/xtypes.h b/xdiff/xtypes.h index 979586f20a..bda1f85eb0 100644 --- a/xdiff/xtypes.h +++ b/xdiff/xtypes.h@@ -48,7 +48,7 @@ typedef struct s_xrecord { typedef struct s_xdfile { xrecord_t *recs; size_t nrec; - ptrdiff_t dstart, dend; + ptrdiff_t dend; bool *changed; size_t *reference_index; size_t nreff;@@ -56,6 +56,7 @@ typedef struct s_xdfile { typedef struct s_xdfenv { xdfile_t xdf1, xdf2; + size_t delta_start; } xdfenv_t;