This is actually v5 of this series, and is being sent due to review comments from a different series, namely en/merge-ort-3[1]. I have rerolls of en/merge-ort-2 and en/merge-ort-3 already prepared, but since gitgitgadget will not allow me to send a series dependent on a not-published-by-Junio series, I cannot yet send them. You will need to temporarily drop them, and I'll resend after you publish the updated version of this series. I do not like this solution, and I was tempted to just push the updates into en/merge-ort-3, but since this series was still hanging in 'seen' awaiting feedback and a lot of the suggestions were for things from this series, I decided to go this route anyway... [1] https://lore.kernel.org/git/CABPp-BHa0zehQd-axmb4bF6fR4PTWwGu9uLjOzgTW8_Gu12iZA@xxxxxxxxxxxxxx/ Changes since v4: * Improved documentation of filemask and dirmask * Improved documentation of merge_result.clean * Added new enum merge_side and documentation with it to try to make the code a bit more self-documenting. Elijah Newren (20): merge-ort: setup basic internal data structures merge-ort: add some high-level algorithm structure merge-ort: port merge_start() from merge-recursive merge-ort: use histogram diff merge-ort: add an err() function similar to one from merge-recursive merge-ort: implement a very basic collect_merge_info() merge-ort: avoid repeating fill_tree_descriptor() on the same tree merge-ort: compute a few more useful fields for collect_merge_info merge-ort: record stage and auxiliary info for every path merge-ort: avoid recursing into identical trees merge-ort: add a preliminary simple process_entries() implementation merge-ort: have process_entries operate in a defined order merge-ort: step 1 of tree writing -- record basenames, modes, and oids merge-ort: step 2 of tree writing -- function to create tree object merge-ort: step 3 of tree writing -- handling subdirectories as we go merge-ort: basic outline for merge_switch_to_result() merge-ort: add implementation of checkout() tree: enable cmp_cache_name_compare() to be used elsewhere merge-ort: add implementation of record_conflicted_index_entries() merge-ort: free data structures in merge_finalize() merge-ort.c | 1248 ++++++++++++++++++++++++++++++++++++++++++++++++++- merge-ort.h | 9 +- tree.c | 2 +- tree.h | 2 + 4 files changed, 1256 insertions(+), 5 deletions(-) base-commit: 3cf59784d42c4152a0b3de7bb7a75d0071e5f878 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-923%2Fnewren%2Fort-basics-v3 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-923/newren/ort-basics-v3 Pull-Request: https://github.com/git/git/pull/923 Range-diff vs v2: 1: 2568ec92c6d ! 1: 518dde86966 merge-ort: setup basic internal data structures @@ merge-ort.c + unsigned df_conflict:1; + + /* -+ * For filemask and dirmask, see tree-walk.h's struct traverse_info, -+ * particularly the documentation above the "fn" member. Note that -+ * filemask = mask & ~dirmask from that documentation. ++ * For filemask and dirmask, the ith bit corresponds to whether the ++ * ith entry is a file (filemask) or a directory (dirmask). Thus, ++ * filemask & dirmask is always zero, and filemask | dirmask is at ++ * most 7 but can be less when a path does not appear as either a ++ * file or a directory on at least one side of history. ++ * ++ * Note that these masks are related to enum merge_side, as the ith ++ * entry corresponds to side i. ++ * ++ * These values come from a traverse_trees() call; more info may be ++ * found looking at tree-walk.h's struct traverse_info, ++ * particularly the documentation above the "fn" member (note that ++ * filemask = mask & ~dirmask from that documentation). + */ + unsigned filemask:3; + unsigned dirmask:3; 2: b658536f59d = 2: 5827ec7f3eb merge-ort: add some high-level algorithm structure 3: acb40f5c165 = 3: 8295591ee13 merge-ort: port merge_start() from merge-recursive 4: 22fecf6ccd1 = 4: 38b4f9cf78c merge-ort: use histogram diff 5: 6c4c0c15b3d ! 5: 95143bebf09 merge-ort: add an err() function similar to one from merge-recursive @@ Commit message for when we detect problems returned from collect_merge_info()'s traverse_trees() call, which we will be adding next. + While we are at it, also add more documentation for the "clean" field + from struct merge_result, particularly since the name suggests a boolean + but it is not quite one and this is our first non-boolean usage. + Signed-off-by: Elijah Newren <newren@xxxxxxxxx> ## merge-ort.c ## @@ merge-ort.c: static void merge_ort_nonrecursive_internal(struct merge_options *o result->clean = detect_and_process_renames(opt, merge_base, side1, side2); process_entries(opt, &working_tree_oid); + + ## merge-ort.h ## +@@ merge-ort.h: struct commit; + struct tree; + + struct merge_result { +- /* Whether the merge is clean */ ++ /* ++ * Whether the merge is clean; possible values: ++ * 1: clean ++ * 0: not clean (merge conflicts) ++ * <0: operation aborted prematurely. (object database ++ * unreadable, disk full, etc.) Worktree may be left in an ++ * inconsistent state if operation failed near the end. ++ */ + int clean; + + /* 6: 27268ef8a3c ! 6: 242f6462ebb merge-ort: implement a very basic collect_merge_info() @@ Commit message Signed-off-by: Elijah Newren <newren@xxxxxxxxx> ## merge-ort.c ## +@@ + #include "tree.h" + #include "xdiff-interface.h" + ++/* ++ * We have many arrays of size 3. Whenever we have such an array, the ++ * indices refer to one of the sides of the three-way merge. This is so ++ * pervasive that the constants 0, 1, and 2 are used in many places in the ++ * code (especially in arithmetic operations to find the other side's index ++ * or to compute a relevant mask), but sometimes these enum names are used ++ * to aid code clarity. ++ * ++ * See also 'filemask' and 'dirmask' in struct conflict_info; the "ith side" ++ * referred to there is one of these three sides. ++ */ ++enum merge_side { ++ MERGE_BASE = 0, ++ MERGE_SIDE1 = 1, ++ MERGE_SIDE2 = 2 ++}; ++ + struct merge_options_internal { + /* + * paths: primary data structure in all of merge ort. @@ merge-ort.c: static int err(struct merge_options *opt, const char *err, ...) return -1; } @@ merge-ort.c: static int err(struct merge_options *opt, const char *err, ...) + newinfo.namelen = p->pathlen; + newinfo.pathlen = st_add3(newinfo.pathlen, p->pathlen, 1); + -+ for (i = 0; i < 3; i++) { ++ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) { + const struct object_id *oid = NULL; + if (dirmask & 1) + oid = &names[i].oid; @@ merge-ort.c: static int err(struct merge_options *opt, const char *err, ...) + ret = traverse_trees(NULL, 3, t, &newinfo); + opti->current_dir_name = original_dir_name; + -+ for (i = 0; i < 3; i++) ++ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) + free(buf[i]); + + if (ret < 0) 7: c6e5621c210 ! 7: c18bdc1b052 merge-ort: avoid repeating fill_tree_descriptor() on the same tree @@ merge-ort.c: static int collect_merge_info_callback(int n, @@ merge-ort.c: static int collect_merge_info_callback(int n, newinfo.pathlen = st_add3(newinfo.pathlen, p->pathlen, 1); - for (i = 0; i < 3; i++) { + for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) { - const struct object_id *oid = NULL; - if (dirmask & 1) - oid = &names[i].oid; 8: 93fd69fa3c6 ! 8: be5708dc628 merge-ort: compute a few more useful fields for collect_merge_info @@ merge-ort.c: static int collect_merge_info_callback(int n, + * the beginning of this function). + */ - for (i = 0; i < 3; i++) { + for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) { if (i == 1 && side1_matches_mbase) 9: decff4b3754 ! 9: be4bdfac876 merge-ort: record stage and auxiliary info for every path @@ merge-ort.c: static int err(struct merge_options *opt, const char *err, ...) + struct conflict_info *ci; + + ASSIGN_AND_VERIFY_CI(ci, mi); -+ for (i = 0; i < 3; i++) { ++ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) { + ci->pathnames[i] = fullpath; + ci->stages[i].mode = names[i].mode; + oidcpy(&ci->stages[i].oid, &names[i].oid); 10: 86c661fe1ee = 10: 6fdf85c8f1a merge-ort: avoid recursing into identical trees 11: aa3b13ffd87 = 11: 8b001ae643a merge-ort: add a preliminary simple process_entries() implementation 12: b54306fd0e6 = 12: 260b12290fb merge-ort: have process_entries operate in a defined order 13: 8ee8561d7a3 = 13: 092e77bbb15 merge-ort: step 1 of tree writing -- record basenames, modes, and oids 14: 6ff56824c33 = 14: b5d9ba10f8c merge-ort: step 2 of tree writing -- function to create tree object 15: da4fe900496 = 15: 81374cbf205 merge-ort: step 3 of tree writing -- handling subdirectories as we go 16: 8e90d211c5d = 16: 3198efe3188 merge-ort: basic outline for merge_switch_to_result() 17: 61fada146cf ! 17: 119f40c77f8 merge-ort: add implementation of checkout() @@ merge-ort.c +#include "unpack-trees.h" #include "xdiff-interface.h" - struct merge_options_internal { + /* @@ merge-ort.c: static int checkout(struct merge_options *opt, struct tree *prev, struct tree *next) 18: f5a13a0b084 = 18: b4c400051ad tree: enable cmp_cache_name_compare() to be used elsewhere 19: 4efac38116d ! 19: ee831c8cece merge-ort: add implementation of record_conflicted_index_entries() @@ merge-ort.c: static int record_conflicted_index_entries(struct merge_options *op + ce->ce_flags |= CE_REMOVE; + } + -+ for (i = 0; i < 3; i++) { ++ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) { + struct version_info *vi; + if (!(ci->filemask & (1ul << i))) + continue; 20: fbeb527d671 = 20: 55451a79eec merge-ort: free data structures in merge_finalize() -- gitgitgadget
