[PATCH v3] rev-list: support human-readable output for `--disk-usage`

From: Li Linchao <lilinchao@oschina.cn>

The '--disk-usage' option for git-rev-list was introduced in 16950f8384 (rev-list: add --disk-usage option for calculating disk usage, 2021-02-09). This is very useful for people inspect their git repo's objects usage infomation, but the resulting number is quit hard for a human to read.

Teach git rev-list to output a human readable result when using '--disk-usage'.

Signed-off-by: Li Linchao <lilinchao@oschina.cn>
---
    rev-list: support human-readable output for disk-usage
    
    The '--disk-usage' option for git-rev-list was introduced in 16950f8384
    (rev-list: add --disk-usage option for calculating disk usage,
    2021-02-09). This is very useful for people inspect their git repo's
    objects usage infomation, but the result number is quit hard for human
    to read.
    
    Teach git rev-list to output more human readable result when using
    '--disk-usage' to calculate objects disk usage.
    
    Signed-off-by: Li Linchao lilinchao@oschina.cn

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1313%2FCactusinhand%2Fllc%2Fadd-human-readable-option-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1313/Cactusinhand/llc/add-human-readable-option-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/1313

Range-diff vs v2:

 1:  7e34d16efe4 ! 1:  000a6b37ec9 rev-list: support human-readable output for `--disk-usage`
     @@ builtin/rev-list.c: static int arg_show_object_names = 1;
       
       static off_t get_object_disk_usage(struct object *obj)
       {
     +@@ builtin/rev-list.c: static int show_object_fast(
     + 	return 1;
     + }
     + 
     ++static void print_disk_usage(off_t size)
     ++{
     ++	struct strbuf sb = STRBUF_INIT;
     ++	if (human_readable)
     ++		strbuf_humanise_bytes(&sb, size);
     ++	else
     ++		strbuf_addf(&sb, "%"PRIuMAX, (uintmax_t)size);
     ++	puts(sb.buf);
     ++	strbuf_release(&sb);
     ++}
     ++
     + static inline int parse_missing_action_value(const char *value)
     + {
     + 	if (!strcmp(value, "error")) {
      @@ builtin/rev-list.c: static int try_bitmap_disk_usage(struct rev_info *revs,
       				 int filter_provided_objects)
       {
       	struct bitmap_index *bitmap_git;
     -+	struct strbuf disk_buf = STRBUF_INIT;
      +	off_t size_from_bitmap;
       
       	if (!show_disk_usage)
     @@ builtin/rev-list.c: static int try_bitmap_disk_usage(struct rev_info *revs,
      -	printf("%"PRIuMAX"\n",
      -	       (uintmax_t)get_disk_usage_from_bitmap(bitmap_git, revs));
      +	size_from_bitmap = get_disk_usage_from_bitmap(bitmap_git, revs);
     -+	if (human_readable)
     -+		strbuf_humanise_bytes(&disk_buf, size_from_bitmap);
     -+	else
     -+		strbuf_addf(&disk_buf, "%"PRIuMAX"", (uintmax_t)size_from_bitmap);
     -+	puts(disk_buf.buf);
     -+	strbuf_release(&disk_buf);
     ++	print_disk_usage(size_from_bitmap);
       	return 0;
       }
       
     @@ builtin/rev-list.c: int cmd_rev_list(int argc, const char **argv, const char *pr
       		}
       
      -		if (!strcmp(arg, "--disk-usage")) {
     --			show_disk_usage = 1;
     --			info.flags |= REV_LIST_QUIET;
     --			continue;
      +		if (skip_prefix(arg, "--disk-usage", &arg)) {
      +			if (*arg == '=') {
      +				if (!strcmp(++arg, "human")) {
      +					human_readable = 1;
     -+					show_disk_usage = 1;
     -+					info.flags |= REV_LIST_QUIET;
     -+					continue;
      +				} else
      +					die(_("invalid value for '%s': '%s', try --disk-usage=human"), "--disk-usage", arg);
     -+			} else {
     -+				show_disk_usage = 1;
     -+				info.flags |= REV_LIST_QUIET;
     -+				continue;
     ++			} else if (*arg) {
     ++				/*
     ++				* Arguably should goto a label to continue chain of ifs?
     ++				* Doesn't matter unless we try to add --disk-usage-foo
     ++				* afterwards
     ++				*/
     ++				usage(rev_list_usage);
      +			}
     - 		}
     - 
     - 		usage(rev_list_usage);
     + 			show_disk_usage = 1;
     + 			info.flags |= REV_LIST_QUIET;
     + 			continue;
      @@ builtin/rev-list.c: int cmd_rev_list(int argc, const char **argv, const char *prefix)
     - 			printf("%d\n", revs.count_left + revs.count_right);
       	}
       
     --	if (show_disk_usage)
     + 	if (show_disk_usage)
      -		printf("%"PRIuMAX"\n", (uintmax_t)total_disk_usage);
     -+	if (show_disk_usage) {
     -+		struct strbuf disk_buf = STRBUF_INIT;
     -+		if (human_readable)
     -+			strbuf_humanise_bytes(&disk_buf, total_disk_usage);
     -+		else
     -+			strbuf_addf(&disk_buf, "%"PRIuMAX"", (uintmax_t)total_disk_usage);
     -+		puts(disk_buf.buf);
     -+		strbuf_release(&disk_buf);
     -+	}
     ++		print_disk_usage(total_disk_usage);
       
       cleanup:
       	release_revisions(&revs);

 Documentation/rev-list-options.txt |  5 ++++-
 builtin/rev-list.c                 | 35 ++++++++++++++++++++++++++----
 t/t6115-rev-list-du.sh             | 22 +++++++++++++++++++
 3 files changed, 57 insertions(+), 5 deletions(-)