merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/t/perf/repos/.gitignore

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+gen-*/

third_party/git/t/perf/repos/inflate-repo.sh

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+#!/bin/sh
+# Inflate the size of an EXISTING repo.
+#
+# This script should be run inside the worktree of a TEST repo.
+# It will use the contents of the current HEAD to generate a
+# commit containing copies of the current worktree such that the
+# total size of the commit has at least <target_size> files.
+#
+# Usage: [-t target_size] [-b branch_name]
+
+set -e
+
+target_size=10000
+branch_name=p0006-ballast
+ballast=ballast
+
+while test "$#" -ne 0
+do
+    case "$1" in
+	-b)
+	    shift;
+	    test "$#" -ne 0 || { echo 'error: -b requires an argument' >&2; exit 1; }
+	    branch_name=$1;
+	    shift ;;
+	-t)
+	    shift;
+	    test "$#" -ne 0 || { echo 'error: -t requires an argument' >&2; exit 1; }
+	    target_size=$1;
+	    shift ;;
+	*)
+	    echo "error: unknown option '$1'" >&2; exit 1 ;;
+    esac
+done
+
+git ls-tree -r HEAD >GEN_src_list
+nr_src_files=$(cat GEN_src_list | wc -l)
+
+src_branch=$(git symbolic-ref --short HEAD)
+
+echo "Branch $src_branch initially has $nr_src_files files."
+
+if test $target_size -le $nr_src_files
+then
+    echo "Repository already exceeds target size $target_size."
+    rm GEN_src_list
+    exit 1
+fi
+
+# Create well-known branch and add 1 file change to start
+# if off before the ballast.
+git checkout -b $branch_name HEAD
+echo "$target_size" > inflate-repo.params
+git add inflate-repo.params
+git commit -q -m params
+
+# Create ballast for in our branch.
+copy=1
+nr_files=$nr_src_files
+while test $nr_files -lt $target_size
+do
+    sed -e "s|	|	$ballast/$copy/|" <GEN_src_list |
+	git update-index --index-info
+
+    nr_files=$(expr $nr_files + $nr_src_files)
+    copy=$(expr $copy + 1)
+done
+rm GEN_src_list
+git commit -q -m "ballast"
+
+# Modify 1 file and commit.
+echo "$target_size" >> inflate-repo.params
+git add inflate-repo.params
+git commit -q -m "ballast plus 1"
+
+nr_files=$(git ls-files | wc -l)
+
+# Checkout master to put repo in canonical state (because
+# the perf test may need to clone and enable sparse-checkout
+# before attempting to checkout a commit with the ballast
+# (because it may contain 100K directories and 1M files)).
+git checkout $src_branch
+
+echo "Repository inflated. Branch $branch_name has $nr_files files."
+
+exit 0

third_party/git/t/perf/repos/many-files.sh

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+#!/bin/sh
+# Generate test data repository using the given parameters.
+# When omitted, we create "gen-many-files-d-w-f.git".
+#
+# Usage: [-r repo] [-d depth] [-w width] [-f files]
+#
+# -r repo: path to the new repo to be generated
+# -d depth: the depth of sub-directories
+# -w width: the number of sub-directories at each level
+# -f files: the number of files created in each directory
+#
+# Note that all files will have the same SHA-1 and each
+# directory at a level will have the same SHA-1, so we
+# will potentially have a large index, but not a large
+# ODB.
+#
+# Ballast will be created under "ballast/".
+
+EMPTY_BLOB=e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
+
+set -e
+
+# (5, 10, 9) will create 999,999 ballast files.
+# (4, 10, 9) will create  99,999 ballast files.
+depth=5
+width=10
+files=9
+
+while test "$#" -ne 0
+do
+    case "$1" in
+	-r)
+	    shift;
+	    test "$#" -ne 0 || { echo 'error: -r requires an argument' >&2; exit 1; }
+	    repo=$1;
+	    shift ;;
+	-d)
+	    shift;
+	    test "$#" -ne 0 || { echo 'error: -d requires an argument' >&2; exit 1; }
+	    depth=$1;
+	    shift ;;
+	-w)
+	    shift;
+	    test "$#" -ne 0 || { echo 'error: -w requires an argument' >&2; exit 1; }
+	    width=$1;
+	    shift ;;
+	-f)
+	    shift;
+	    test "$#" -ne 0 || { echo 'error: -f requires an argument' >&2; exit 1; }
+	    files=$1;
+	    shift ;;
+	*)
+	    echo "error: unknown option '$1'" >&2; exit 1 ;;
+	esac
+done
+
+# Inflate the index with thousands of empty files.
+# usage: dir depth width files
+fill_index() {
+	awk -v arg_dir=$1 -v arg_depth=$2 -v arg_width=$3 -v arg_files=$4 '
+		function make_paths(dir, depth, width, files, f, w) {
+			for (f = 1; f <= files; f++) {
+				print dir "/file" f
+			}
+			if (depth > 0) {
+				for (w = 1; w <= width; w++) {
+					make_paths(dir "/dir" w, depth - 1, width, files)
+				}
+			}
+		}
+		END { make_paths(arg_dir, arg_depth, arg_width, arg_files) }
+		' </dev/null |
+	sed "s/^/100644 $EMPTY_BLOB	/" |
+	git update-index --index-info
+	return 0
+}
+
+[ -z "$repo" ] && repo=gen-many-files-$depth.$width.$files.git
+
+mkdir $repo
+cd $repo
+git init .
+
+# Create an initial commit just to define master.
+touch many-files.empty
+echo "$depth $width $files" >many-files.params
+git add many-files.*
+git commit -q -m params
+
+# Create ballast for p0006 based upon the given params and
+# inflate the index with thousands of empty files and commit.
+git checkout -b p0006-ballast
+fill_index "ballast" $depth $width $files
+git commit -q -m "ballast"
+
+nr_files=$(git ls-files | wc -l)
+
+# Modify 1 file and commit.
+echo "$depth $width $files" >>many-files.params
+git add many-files.params
+git commit -q -m "ballast plus 1"
+
+# Checkout master to put repo in canonical state (because
+# the perf test may need to clone and enable sparse-checkout
+# before attempting to checkout a commit with the ballast
+# (because it may contain 100K directories and 1M files)).
+git checkout master
+
+echo "Repository "$repo" ($depth, $width, $files) created.  Ballast $nr_files."
+exit 0