Re: What's cooking in git.git (Jan 2016, #02; Mon, 11)
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jan 13, 2016, 23:54 UTC
- Message-ID
- <xmqqlh7tkpcy.fsf@gitster.mtv.corp.google.com>
- In-Reply-To
- <xmqqpox5kpsy.fsf@gitster.mtv.corp.google.com>
Junio C Hamano <gitster@pobox.com> writes:
Show 18 quoted lines
> My plan is to use a function pointer to switch between them. A code > like the above in practice look more like > > (1) there is a config/option parser that sets line_terminator that > is typically a file-scope global. > > if (z_option) > line_terminator = '\0'; > else > line_terminator = '\n'; > > (2) the callsite calls getline with it > > strbuf_getline(..., line_terminator); > > So we can introduce a file-scope global, (*getline_fn)(), and then > tweak (1) by removing line_terminator and replacing the assignment > with an assignment to getline_fn.
And after doing the obvious wholesale replacement on callers that hardcode either '\n' or '\0' with this:
#!/bin/sh perl -i -p -e ' s/strbuf_getline\((.*?), '\''\\n'\''\)/strbuf_getline_lf($1)/g; s/strbuf_getline\((.*?), '\''\\0'\''\)/strbuf_getline_nul($1)/g; ' "$@"
the only direct callers of strbuf_getline() that remain in the tree are check-attr, check-ignore, checkout-index and mktree.
And the conversion of mktree would look like this. I might further tweak it to rename and flip the polarity of lf_lines to nul_lines, but I do not think that matters very much.
builtin/mktree.c | 15 +++++++++------ strbuf.h | 3 +++ 2 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/builtin/mktree.c b/builtin/mktree.c index a964d6b..7633d35 100644 --- a/builtin/mktree.c +++ b/builtin/mktree.c @@ -65,7 +65,7 @@ static const char *mktree_usage[] = { NULL }; -static void mktree_line(char *buf, size_t len, int line_termination, int allow_missing) +static void mktree_line(char *buf, size_t len, int lf_lines, int allow_missing) { char *ptr, *ntr; unsigned mode; @@ -97,7 +97,7 @@ static void mktree_line(char *buf, size_t len, int line_termination, int allow_m *ntr++ = 0; /* now at the beginning of SHA1 */ path = ntr + 41; /* at the beginning of name */ - if (line_termination && path[0] == '"') { + if (lf_lines && path[0] == '"') { struct strbuf p_uq = STRBUF_INIT; if (unquote_c_style(&p_uq, path, NULL)) die("invalid quoting"); @@ -141,13 +141,14 @@ int cmd_mktree(int ac, const char **av, const char *prefix) { struct strbuf sb = STRBUF_INIT; unsigned char sha1[20]; - int line_termination = '\n'; + int lf_lines = 1; int allow_missing = 0; int is_batch_mode = 0; int got_eof = 0; + strbuf_getline_fn getline_fn; const struct option option[] = { - OPT_SET_INT('z', NULL, &line_termination, N_("input is NUL terminated"), '\0'), + OPT_SET_INT('z', NULL, &lf_lines, N_("input is NUL terminated"), '\0'), OPT_SET_INT( 0 , "missing", &allow_missing, N_("allow missing objects"), 1), OPT_SET_INT( 0 , "batch", &is_batch_mode, N_("allow creation of more than one tree"), 1), OPT_END() @@ -155,9 +156,11 @@ int cmd_mktree(int ac, const char **av, const char *prefix) ac = parse_options(ac, av, prefix, option, mktree_usage, 0); + getline_fn = lf_lines ? strbuf_getline_lf : strbuf_getline_nul; + while (!got_eof) { while (1) { - if (strbuf_getline(&sb, stdin, line_termination) == EOF) { + if (getline_fn(&sb, stdin) == EOF) { got_eof = 1; break; } @@ -167,7 +170,7 @@ int cmd_mktree(int ac, const char **av, const char *prefix) break; die("input format error: (blank line only valid in batch mode)"); } - mktree_line(sb.buf, sb.len, line_termination, allow_missing); + mktree_line(sb.buf, sb.len, lf_lines, allow_missing); } if (is_batch_mode && got_eof && used < 1) { /* diff --git a/strbuf.h b/strbuf.h index db053be..9c8d715 100644 --- a/strbuf.h +++ b/strbuf.h @@ -405,6 +405,9 @@ static inline int strbuf_getline_nul(struct strbuf *sb, FILE *fp) return strbuf_getline(sb, fp, '\0'); } +typedef int (*strbuf_getline_fn)(struct strbuf *, FILE *); + + /** * Like `strbuf_getline`, but keeps the trailing terminator (if * any) in the buffer.