[PATCH 2/5] t6421: add tests checking for excessive object downloads during merge
Show changes to t/t6421-merge-partial-clone.sh +433 −0
diff --git a/t/t6421-merge-partial-clone.sh b/t/t6421-merge-partial-clone.sh
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+#!/bin/sh
+
+test_description="limiting blob downloads when merging with partial clones"
+# Uses a methodology similar to
+# t6042: corner cases with renames but not criss-cross merges
+# t6036: corner cases with both renames and criss-cross merges
+# t6423: directory rename detection
+#
+# The setup for all of them, pictorially, is:
+#
+# A
+# o
+# / \
+# O o ?
+# \ /
+# o
+# B
+#
+# To help make it easier to follow the flow of tests, they have been
+# divided into sections and each test will start with a quick explanation
+# of what commits O, A, and B contain.
+#
+# Notation:
+# z/{b,c} means files z/b and z/c both exist
+# x/d_1 means file x/d exists with content d1. (Purpose of the
+# underscore notation is to differentiate different
+# files that might be renamed into each other's paths.)
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-merge.sh
+
+test_setup_repo () {
+ test -d server && return
+ test_create_repo server &&
+ (
+ cd server &&
+
+ git config uploadpack.allowfilter 1 &&
+ git config uploadpack.allowanysha1inwant 1 &&
+
+ mkdir -p general &&
+ test_seq 2 9 >general/leap1 &&
+ cp general/leap1 general/leap2 &&
+ echo leap2 >>general/leap2 &&
+
+ mkdir -p basename &&
+ cp general/leap1 basename/numbers &&
+ cp general/leap1 basename/sequence &&
+ cp general/leap1 basename/values &&
+ echo numbers >>basename/numbers &&
+ echo sequence >>basename/sequence &&
+ echo values >>basename/values &&
+
+ mkdir -p dir/unchanged &&
+ mkdir -p dir/subdir/tweaked &&
+ echo a >dir/subdir/a &&
+ echo b >dir/subdir/b &&
+ echo c >dir/subdir/c &&
+ echo d >dir/subdir/d &&
+ echo e >dir/subdir/e &&
+ cp general/leap1 dir/subdir/Makefile &&
+ echo toplevel makefile >>dir/subdir/Makefile &&
+ echo f >dir/subdir/tweaked/f &&
+ echo g >dir/subdir/tweaked/g &&
+ echo h >dir/subdir/tweaked/h &&
+ echo subdirectory makefile >dir/subdir/tweaked/Makefile &&
+ for i in `test_seq 1 88`; do
+ echo content $i >dir/unchanged/file_$i
+ done &&
+ git add . &&
+ git commit -m "O" &&
+
+ git branch O &&
+ git branch A &&
+ git branch B-single &&
+ git branch B-dir &&
+ git branch B-many &&
+
+ git switch A &&
+
+ git rm general/leap* &&
+ mkdir general/ &&
+ test_seq 1 9 >general/jump1 &&
+ cp general/jump1 general/jump2 &&
+ echo leap2 >>general/jump2 &&
+
+ rm basename/numbers basename/sequence basename/values &&
+ mkdir -p basename/subdir/
+ cp general/jump1 basename/subdir/numbers &&
+ cp general/jump1 basename/subdir/sequence &&
+ cp general/jump1 basename/subdir/values &&
+ echo numbers >>basename/subdir/numbers &&
+ echo sequence >>basename/subdir/sequence &&
+ echo values >>basename/subdir/values &&
+
+ git rm dir/subdir/tweaked/f &&
+ echo more >>dir/subdir/e &&
+ echo more >>dir/subdir/Makefile &&
+ echo more >>dir/subdir/tweaked/Makefile &&
+ mkdir dir/subdir/newsubdir &&
+ echo rust code >dir/subdir/newsubdir/newfile.rs &&
+ git mv dir/subdir/e dir/subdir/newsubdir/ &&
+ git mv dir folder &&
+ git add . &&
+ git commit -m "A" &&
+
+ git switch B-single &&
+ echo new first line >dir/subdir/Makefile &&
+ cat general/leap1 >>dir/subdir/Makefile &&
+ echo toplevel makefile >>dir/subdir/Makefile &&
+ echo perl code >general/newfile.pl &&
+ git add . &&
+ git commit -m "B-single" &&
+
+ git switch B-dir &&
+ echo java code >dir/subdir/newfile.java &&
+ echo scala code >dir/subdir/newfile.scala &&
+ echo groovy code >dir/subdir/newfile.groovy &&
+ git add . &&
+ git commit -m "B-dir" &&
+
+ git switch B-many &&
+ test_seq 2 10 >general/leap1 &&
+ rm general/leap2 &&
+ cp general/leap1 general/leap2 &&
+ echo leap2 >>general/leap2 &&
+
+ rm basename/numbers basename/sequence basename/values &&
+ mkdir -p basename/subdir/
+ cp general/leap1 basename/subdir/numbers &&
+ cp general/leap1 basename/subdir/sequence &&
+ cp general/leap1 basename/subdir/values &&
+ echo numbers >>basename/subdir/numbers &&
+ echo sequence >>basename/subdir/sequence &&
+ echo values >>basename/subdir/values &&
+
+ mkdir dir/subdir/newsubdir/ &&
+ echo c code >dir/subdir/newfile.c &&
+ echo python code >dir/subdir/newsubdir/newfile.py &&
+ git add . &&
+ git commit -m "B-many" &&
+
+ git switch A
+ )
+}
+
+# Testcase: Objects downloaded for single relevant rename
+# Commit O:
+# general/{leap1_O, leap2_O}
+# basename/{numbers_O, sequence_O, values_O}
+# dir/subdir/{a,b,c,d,e_O,Makefile_TOP_O}
+# dir/subdir/tweaked/{f,g,h,Makefile_SUB_O}
+# dir/unchanged/<LOTS OF FILES>
+# Commit A:
+# (Rename leap->jump, rename basename/ -> basename/subdir/, rename dir/
+# -> folder/, move e into newsubdir, add newfile.rs, remove f, modify
+# both both Makefiles and jumps)
+# general/{jump1_A, jump2_A}
+# basename/subdir/{numbers_A, sequence_A, values_A}
+# folder/subdir/{a,b,c,d,Makefile_TOP_A}
+# folder/subdir/newsubdir/{e_A,newfile.rs}
+# folder/subdir/tweaked/{g,h,Makefile_SUB_A}
+# folder/unchanged/<LOTS OF FILES>
+# Commit B(-single):
+# (add newfile.pl, tweak Makefile_TOP)
+# general/{leap1_O, leap2_O,newfile.pl}
+# basename/{numbers_O, sequence_O, values_O}
+# dir/{a,b,c,d,e_O,Makefile_TOP_B}
+# dir/tweaked/{f,g,h,Makefile_SUB_O}
+# dir/unchanged/<LOTS OF FILES>
+# Expected:
+# general/{jump1_A, jump2_A,newfile.pl}
+# basename/subdir/{numbers_A, sequence_A, values_A}
+# folder/subdir/{a,b,c,d,Makefile_TOP_Merged}
+# folder/subdir/newsubdir/{e_A,newfile.rs}
+# folder/subdir/tweaked/{g,h,Makefile_SUB_A}
+# folder/unchanged/<LOTS OF FILES>
+#
+# Objects that need to be fetched:
+# Rename detection:
+# Side1 (O->A):
+# Basename-matches rename detection only needs to fetch these objects:
+# Makefile_TOP_O, Makefile_TOP_A
+# (Despite many renames, all others are content irrelevant. They
+# are also location irrelevant because newfile.rs was added on
+# the side doing the directory rename, and newfile.pl was added to
+# a directory that was not renamed on either side.)
+# General rename detection only needs to fetch these objects:
+# <None>
+# (Even though newfile.rs, jump[12], basename/subdir/*, and e
+# could all be used as destinations in rename detection, the
+# basename detection for Makefile matches up all relevant
+# sources, so these other files never end up needing to be
+# used)
+# Side2 (O->B):
+# Basename-matches rename detection only needs to fetch these objects:
+# <None>
+# (there are no deleted files, so no possible sources)
+# General rename detection only needs to fetch these objects:
+# <None>
+# (there are no deleted files, so no possible sources)
+# Merge:
+# 3-way content merge needs to grab these objects:
+# Makefile_TOP_B
+# Nothing else needs to fetch objects
+#
+# Summary: 2 fetches (1 for 2 objects, 1 for 1 object)
+#
+test_expect_merge_algorithm failure failure 'Objects downloaded for single relevant rename' '
+ test_setup_repo &&
+ git clone --sparse --filter=blob:none "file://$(pwd)/server" objects-single &&
+ (
+ cd objects-single &&
+
+ git rev-list --objects --all --missing=print |
+ grep '\?' >missing-objects-before &&
+
+ git checkout -q origin/A &&
+
+ GIT_TRACE2_PERF="$(pwd)/trace.output" git -c merge.directoryRenames=true merge --no-stat --no-progress origin/B-single &&
+
+ # Check the number of objects we reported we would fetch
+ cat >expect <<-EOF &&
+ ..........fetch_count:2
+ ......fetch_count:1
+ EOF
+ grep fetch_count trace.output | cut -d "|" -f 9 >actual &&
+ test_cmp expect actual &&
+
+ # Check the number of fetch commands exec-ed
+ grep d0.*fetch.negotiationAlgorithm trace.output >fetches &&
+ test_line_count = 2 fetches &&
+
+ git rev-list --objects --all --missing=print |
+ grep ^? >missing-objects-after &&
+ test_cmp missing-objects-before missing-objects-after |
+ grep "^[-+]?" >found-and-new-objects &&
+ # We should not have any NEW missing objects
+ ! grep ^+ found-and-new-objects &&
+ # Fetched 2+1=3 objects, so should have 3 fewer missing objects
+ test_line_count = 3 found-and-new-objects
+ )
+'
+
+# Testcase: Objects downloaded for directory rename
+# Commit O:
+# general/{leap1_O, leap2_O}
+# basename/{numbers_O, sequence_O, values_O}
+# dir/subdir/{a,b,c,d,e_O,Makefile_TOP_O}
+# dir/subdir/tweaked/{f,g,h,Makefile_SUB_O}
+# dir/unchanged/<LOTS OF FILES>
+# Commit A:
+# (Rename leap->jump, rename basename/ -> basename/subdir/, rename dir/ ->
+# folder/, move e into newsubdir, add newfile.rs, remove f, modify
+# both Makefiles and jumps)
+# general/{jump1_A, jump2_A}
+# basename/subdir/{numbers_A, sequence_A, values_A}
+# folder/subdir/{a,b,c,d,Makefile_TOP_A}
+# folder/subdir/newsubdir/{e_A,newfile.rs}
+# folder/subdir/tweaked/{g,h,Makefile_SUB_A}
+# folder/unchanged/<LOTS OF FILES>
+# Commit B(-dir):
+# (add dir/subdir/newfile.{java,scala,groovy}
+# general/{leap1_O, leap2_O}
+# basename/{numbers_O, sequence_O, values_O}
+# dir/subdir/{a,b,c,d,e_O,Makefile_TOP_O,
+# newfile.java,newfile.scala,newfile.groovy}
+# dir/subdir/tweaked/{f,g,h,Makefile_SUB_O}
+# dir/unchanged/<LOTS OF FILES>
+# Expected:
+# general/{jump1_A, jump2_A}
+# basename/subdir/{numbers_A, sequence_A, values_A}
+# folder/subdir/{a,b,c,d,Makefile_TOP_A,
+# newfile.java,newfile.scala,newfile.groovy}
+# folder/subdir/newsubdir/{e_A,newfile.rs}
+# folder/subdir/tweaked/{g,h,Makefile_SUB_A}
+# folder/unchanged/<LOTS OF FILES>
+#
+# Objects that need to be fetched:
+# Makefile_TOP_O, Makefile_TOP_A
+# Makefile_SUB_O, Makefile_SUB_A
+# e_O, e_A
+# * Despite A's rename of jump->leap, those renames are irrelevant.
+# * Despite A's rename of basename/ -> basename/subdir/, those renames are
+# irrelevant.
+# * Because of A's rename of dir/ -> folder/ and B-dir's addition of
+# newfile.* into dir/subdir/, we need to determine directory renames.
+# (Technically, there are enough exact renames to determine directory
+# rename detection, but the current implementation always does
+# basename searching before directory rename detection. Running it
+# also before basename searching would mean doing directory rename
+# detection twice, but it's a bit expensive to do that and cases like
+# this are not all that common.)
+# Summary: 1 fetches for 6 objects
+#
+test_expect_merge_algorithm failure failure 'Objects downloaded when a directory rename triggered' '
+ test_setup_repo &&
+ git clone --sparse --filter=blob:none "file://$(pwd)/server" objects-dir &&
+ (
+ cd objects-dir &&
+
+ git rev-list --objects --all --missing=print |
+ grep '\?' >missing-objects-before &&
+
+ git checkout -q origin/A &&
+
+ GIT_TRACE2_PERF="$(pwd)/trace.output" git -c merge.directoryRenames=true merge --no-stat --no-progress origin/B-dir &&
+
+ # Check the number of objects we reported we would fetch
+ cat >expect <<-EOF &&
+ ..........fetch_count:6
+ EOF
+ grep fetch_count trace.output | cut -d "|" -f 9 >actual &&
+ test_cmp expect actual &&
+
+ # Check the number of fetch commands exec-ed
+ grep d0.*fetch.negotiationAlgorithm trace.output >fetches &&
+ test_line_count = 1 fetches &&
+
+ git rev-list --objects --all --missing=print |
+ grep ^? >missing-objects-after &&
+ test_cmp missing-objects-before missing-objects-after |
+ grep "^[-+]?" >found-and-new-objects &&
+ # We should not have any NEW missing objects
+ ! grep ^+ found-and-new-objects &&
+ # Fetched 6 objects, so should have 6 fewer missing objects
+ test_line_count = 6 found-and-new-objects
+ )
+'
+
+# Testcase: Objects downloaded with lots of renames and modifications
+# Commit O:
+# general/{leap1_O, leap2_O}
+# basename/{numbers_O, sequence_O, values_O}
+# dir/subdir/{a,b,c,d,e_O,Makefile_TOP_O}
+# dir/subdir/tweaked/{f,g,h,Makefile_SUB_O}
+# dir/unchanged/<LOTS OF FILES>
+# Commit A:
+# (Rename leap->jump, rename basename/ -> basename/subdir/, rename dir/
+# -> folder/, move e into newsubdir, add newfile.rs, remove f, modify
+# both both Makefiles and jumps)
+# general/{jump1_A, jump2_A}
+# basename/subdir/{numbers_A, sequence_A, values_A}
+# folder/subdir/{a,b,c,d,Makefile_TOP_A}
+# folder/subdir/newsubdir/{e_A,newfile.rs}
+# folder/subdir/tweaked/{g,h,Makefile_SUB_A}
+# folder/unchanged/<LOTS OF FILES>
+# Commit B(-minimal):
+# (modify both leaps, rename basename/ -> basename/subdir/, add
+# newfile.{c,py})
+# general/{leap1_B, leap2_B}
+# basename/subdir/{numbers_B, sequence_B, values_B}
+# dir/{a,b,c,d,e_O,Makefile_TOP_O,newfile.c}
+# dir/tweaked/{f,g,h,Makefile_SUB_O,newfile.py}
+# dir/unchanged/<LOTS OF FILES>
+# Expected:
+# general/{jump1_Merged, jump2_Merged}
+# basename/subdir/{numbers_Merged, sequence_Merged, values_Merged}
+# folder/subdir/{a,b,c,d,Makefile_TOP_A,newfile.c}
+# folder/subdir/newsubdir/e_A
+# folder/subdir/tweaked/{g,h,Makefile_SUB_A,newfile.py}
+# folder/unchanged/<LOTS OF FILES>
+#
+# Objects that need to be fetched:
+# Rename detection:
+# Side1 (O->A):
+# Basename-matches rename detection only needs to fetch these objects:
+# numbers_O, numbers_A
+# sequence_O, sequence_A
+# values_O, values_A
+# Makefile_TOP_O, Makefile_TOP_A
+# Makefile_SUB_O, Makefile_SUB_A
+# e_O, e_A
+# General rename detection only needs to fetch these objects:
+# leap1_O, leap2_O
+# jump1_A, jump2_A, newfile.rs
+# (only need remaining relevant sources, but any relevant sources need
+# to be matched against all possible unpaired destinations)
+# Side2 (O->B):
+# Basename-matches rename detection only needs to fetch these objects:
+# numbers_B
+# sequence_B
+# values_B
+# (because numbers_O, sequence_O, and values_O already fetched above)
+# General rename detection only needs to fetch these objects:
+# <None>
+# Merge:
+# 3-way content merge needs to grab these objects:
+# leap1_B
+# leap2_B
+# Nothing else needs to fetch objects
+#
+# Summary: 4 fetches (1 for 6 objects, 1 for 8, 1 for 3, 1 for 2)
+#
+test_expect_merge_algorithm failure failure 'Objects downloaded with lots of renames and modifications' '
+ test_setup_repo &&
+ git clone --sparse --filter=blob:none "file://$(pwd)/server" objects-many &&
+ (
+ cd objects-many &&
+
+ git rev-list --objects --all --missing=print |
+ grep '\?' >missing-objects-before &&
+
+ git checkout -q origin/A &&
+
+ GIT_TRACE2_PERF="$(pwd)/trace.output" git -c merge.directoryRenames=true merge --no-stat --no-progress origin/B-many &&
+
+ # Check the number of objects we reported we would fetch
+ cat >expect <<-EOF &&
+ ..........fetch_count:12
+ ..........fetch_count:5
+ ..........fetch_count:3
+ ......fetch_count:2
+ EOF
+ grep fetch_count trace.output | cut -d "|" -f 9 >actual &&
+ test_cmp expect actual &&
+
+ # Check the number of fetch commands exec-ed
+ grep d0.*fetch.negotiationAlgorithm trace.output >fetches &&
+ test_line_count = 4 fetches &&
+
+ git rev-list --objects --all --missing=print |
+ grep ^? >missing-objects-after &&
+ test_cmp missing-objects-before missing-objects-after |
+ grep "^[-+]?" >found-and-new-objects &&
+ # We should not have any NEW missing objects
+ ! grep ^+ found-and-new-objects &&
+ # Fetched 12 + 5 + 3 + 2 == 22 objects
+ test_line_count = 22 found-and-new-objects
+ )
+'
+
+test_done
Elijah Newren via GitGitGadget
