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From: "Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: jonathantanmy@google.com, dstolee@microsoft.com,
	"Elijah Newren" <newren@gmail.com>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Elijah Newren" <newren@gmail.com>,
	"Elijah Newren" <newren@gmail.com>
Subject: [PATCH v2 03/20] merge-ort: port merge_start() from merge-recursive
Date: Fri, 04 Dec 2020 20:47:53 +0000	[thread overview]
Message-ID: <acb40f5c165fa6dd2fe54caee3bcb4f2b24507e3.1607114890.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.923.v2.git.git.1607114890.gitgitgadget@gmail.com>

From: Elijah Newren <newren@gmail.com>

merge_start() basically does a bunch of sanity checks, then allocates
and initializes opt->priv -- a struct merge_options_internal.

Most of the sanity checks are usable as-is.  The
allocation/intialization is a bit different since merge-ort has a very
different merge_options_internal than merge-recursive, but the idea is
the same.

The weirdest part here is that merge-ort and merge-recursive use the
same struct merge_options, even though merge_options has a number of
fields that are oddly specific to merge-recursive's internal
implementation and don't even make sense with merge-ort's high-level
design (e.g. buffer_output, which merge-ort has to always do).  I reused
the same data structure because:
  * most the fields made sense to both merge algorithms
  * making a new struct would have required making new enums or somehow
    externalizing them, and that was getting messy.
  * it simplifies converting the existing callers by not having to
    have different code paths for merge_options setup.

I also marked detect_renames as ignored.  We can revisit that later, but
in short: merge-recursive allowed turning off rename detection because
it was sometimes glacially slow.  When you speed something up by a few
orders of magnitude, it's worth revisiting whether that justification is
still relevant.  Besides, if folks find it's still too slow, perhaps
they have a better scaling case than I could find and maybe it turns up
some more optimizations we can add.  If it still is needed as an option,
it is easy to add later.

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 merge-ort.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/merge-ort.c b/merge-ort.c
index 8c9fea1a5a..f8ac721aa3 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -17,6 +17,8 @@
 #include "cache.h"
 #include "merge-ort.h"
 
+#include "diff.h"
+#include "diffcore.h"
 #include "strmap.h"
 #include "tree.h"
 
@@ -205,7 +207,48 @@ void merge_finalize(struct merge_options *opt,
 
 static void merge_start(struct merge_options *opt, struct merge_result *result)
 {
-	die("Not yet implemented.");
+	/* Sanity checks on opt */
+	assert(opt->repo);
+
+	assert(opt->branch1 && opt->branch2);
+
+	assert(opt->detect_directory_renames >= MERGE_DIRECTORY_RENAMES_NONE &&
+	       opt->detect_directory_renames <= MERGE_DIRECTORY_RENAMES_TRUE);
+	assert(opt->rename_limit >= -1);
+	assert(opt->rename_score >= 0 && opt->rename_score <= MAX_SCORE);
+	assert(opt->show_rename_progress >= 0 && opt->show_rename_progress <= 1);
+
+	assert(opt->xdl_opts >= 0);
+	assert(opt->recursive_variant >= MERGE_VARIANT_NORMAL &&
+	       opt->recursive_variant <= MERGE_VARIANT_THEIRS);
+
+	/*
+	 * detect_renames, verbosity, buffer_output, and obuf are ignored
+	 * fields that were used by "recursive" rather than "ort" -- but
+	 * sanity check them anyway.
+	 */
+	assert(opt->detect_renames >= -1 &&
+	       opt->detect_renames <= DIFF_DETECT_COPY);
+	assert(opt->verbosity >= 0 && opt->verbosity <= 5);
+	assert(opt->buffer_output <= 2);
+	assert(opt->obuf.len == 0);
+
+	assert(opt->priv == NULL);
+
+	/* Initialization of opt->priv, our internal merge data */
+	opt->priv = xcalloc(1, sizeof(*opt->priv));
+
+	/*
+	 * Although we initialize opt->priv->paths with strdup_strings=0,
+	 * that's just to avoid making yet another copy of an allocated
+	 * string.  Putting the entry into paths means we are taking
+	 * ownership, so we will later free it.
+	 *
+	 * In contrast, conflicted just has a subset of keys from paths, so
+	 * we don't want to free those (it'd be a duplicate free).
+	 */
+	strmap_init_with_options(&opt->priv->paths, NULL, 0);
+	strmap_init_with_options(&opt->priv->conflicted, NULL, 0);
 }
 
 /*
-- 
gitgitgadget


  parent reply	other threads:[~2020-12-04 20:50 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-29  7:43 [PATCH 00/20] fundamentals of merge-ort implementation Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 01/20] merge-ort: setup basic internal data structures Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 02/20] merge-ort: add some high-level algorithm structure Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 03/20] merge-ort: port merge_start() from merge-recursive Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 04/20] merge-ort: use histogram diff Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 05/20] merge-ort: add an err() function similar to one from merge-recursive Elijah Newren via GitGitGadget
2020-11-29 10:23   ` Ævar Arnfjörð Bjarmason
2020-11-30 16:56     ` Elijah Newren
2020-11-29 10:26   ` Ævar Arnfjörð Bjarmason
2020-11-29  7:43 ` [PATCH 06/20] merge-ort: implement a very basic collect_merge_info() Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 07/20] merge-ort: avoid repeating fill_tree_descriptor() on the same tree Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 08/20] merge-ort: compute a few more useful fields for collect_merge_info Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 09/20] merge-ort: record stage and auxiliary info for every path Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 10/20] merge-ort: avoid recursing into identical trees Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 11/20] merge-ort: add a preliminary simple process_entries() implementation Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 12/20] merge-ort: have process_entries operate in a defined order Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 13/20] merge-ort: step 1 of tree writing -- record basenames, modes, and oids Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 14/20] merge-ort: step 2 of tree writing -- function to create tree object Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 15/20] merge-ort: step 3 of tree writing -- handling subdirectories as we go Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 16/20] merge-ort: basic outline for merge_switch_to_result() Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 17/20] merge-ort: add implementation of checkout() Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 18/20] tree: enable cmp_cache_name_compare() to be used elsewhere Elijah Newren via GitGitGadget
2020-11-29  7:43 ` [PATCH 19/20] merge-ort: add implementation of record_conflicted_index_entries() Elijah Newren via GitGitGadget
2020-11-29 10:20   ` Ævar Arnfjörð Bjarmason
2020-11-29  7:43 ` [PATCH 20/20] merge-ort: free data structures in merge_finalize() Elijah Newren via GitGitGadget
2020-11-29  7:47 ` [PATCH 00/20] fundamentals of merge-ort implementation Elijah Newren
2020-12-04 20:47 ` [PATCH v2 " Elijah Newren via GitGitGadget
2020-12-04 20:47   ` [PATCH v2 01/20] merge-ort: setup basic internal data structures Elijah Newren via GitGitGadget
2020-12-04 20:47   ` [PATCH v2 02/20] merge-ort: add some high-level algorithm structure Elijah Newren via GitGitGadget
2020-12-04 20:47   ` Elijah Newren via GitGitGadget [this message]
2020-12-04 20:47   ` [PATCH v2 04/20] merge-ort: use histogram diff Elijah Newren via GitGitGadget
2020-12-04 20:47   ` [PATCH v2 05/20] merge-ort: add an err() function similar to one from merge-recursive Elijah Newren via GitGitGadget
2020-12-04 20:47   ` [PATCH v2 06/20] merge-ort: implement a very basic collect_merge_info() Elijah Newren via GitGitGadget
2020-12-04 20:47   ` [PATCH v2 07/20] merge-ort: avoid repeating fill_tree_descriptor() on the same tree Elijah Newren via GitGitGadget
2020-12-04 20:47   ` [PATCH v2 08/20] merge-ort: compute a few more useful fields for collect_merge_info Elijah Newren via GitGitGadget
2020-12-04 20:47   ` [PATCH v2 09/20] merge-ort: record stage and auxiliary info for every path Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 10/20] merge-ort: avoid recursing into identical trees Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 11/20] merge-ort: add a preliminary simple process_entries() implementation Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 12/20] merge-ort: have process_entries operate in a defined order Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 13/20] merge-ort: step 1 of tree writing -- record basenames, modes, and oids Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 14/20] merge-ort: step 2 of tree writing -- function to create tree object Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 15/20] merge-ort: step 3 of tree writing -- handling subdirectories as we go Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 16/20] merge-ort: basic outline for merge_switch_to_result() Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 17/20] merge-ort: add implementation of checkout() Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 18/20] tree: enable cmp_cache_name_compare() to be used elsewhere Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 19/20] merge-ort: add implementation of record_conflicted_index_entries() Elijah Newren via GitGitGadget
2020-12-04 20:48   ` [PATCH v2 20/20] merge-ort: free data structures in merge_finalize() Elijah Newren via GitGitGadget
2020-12-13  8:04   ` [PATCH v3 00/20] fundamentals of merge-ort implementation Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 01/20] merge-ort: setup basic internal data structures Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 02/20] merge-ort: add some high-level algorithm structure Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 03/20] merge-ort: port merge_start() from merge-recursive Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 04/20] merge-ort: use histogram diff Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 05/20] merge-ort: add an err() function similar to one from merge-recursive Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 06/20] merge-ort: implement a very basic collect_merge_info() Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 07/20] merge-ort: avoid repeating fill_tree_descriptor() on the same tree Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 08/20] merge-ort: compute a few more useful fields for collect_merge_info Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 09/20] merge-ort: record stage and auxiliary info for every path Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 10/20] merge-ort: avoid recursing into identical trees Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 11/20] merge-ort: add a preliminary simple process_entries() implementation Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 12/20] merge-ort: have process_entries operate in a defined order Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 13/20] merge-ort: step 1 of tree writing -- record basenames, modes, and oids Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 14/20] merge-ort: step 2 of tree writing -- function to create tree object Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 15/20] merge-ort: step 3 of tree writing -- handling subdirectories as we go Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 16/20] merge-ort: basic outline for merge_switch_to_result() Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 17/20] merge-ort: add implementation of checkout() Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 18/20] tree: enable cmp_cache_name_compare() to be used elsewhere Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 19/20] merge-ort: add implementation of record_conflicted_index_entries() Elijah Newren via GitGitGadget
2020-12-13  8:04     ` [PATCH v3 20/20] merge-ort: free data structures in merge_finalize() Elijah Newren via GitGitGadget
2020-12-14 14:24     ` [PATCH v3 00/20] fundamentals of merge-ort implementation Felipe Contreras
2020-12-14 16:24       ` Elijah Newren
  -- strict thread matches above, loose matches on Subject: below --
2020-11-02 20:43 [PATCH v2 " Elijah Newren
2020-11-02 20:43 ` [PATCH v2 03/20] merge-ort: port merge_start() from merge-recursive Elijah Newren
2020-11-11 13:52   ` Derrick Stolee
2020-11-11 16:22     ` Elijah Newren

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