Revision 218aa3a6162b80696a82b8745daa38fa826985ae authored by Jeff King on 13 June 2014, 06:32:11 UTC, committed by Junio C Hamano on 13 June 2014, 19:10:13 UTC
When we call show_signature or show_mergetag, we read the commit object fresh via read_sha1_file and reparse its headers. However, in most cases we already have the object data available, attached to the "struct commit". This is partially laziness in dealing with the memory allocation issues, but partially defensive programming, in that we would always want to verify a clean version of the buffer (not one that might have been munged by other users of the commit). However, we do not currently ever munge the commit buffer, and not using the already-available buffer carries a fairly big performance penalty when we are looking at a large number of commits. Here are timings on linux.git: [baseline, no signatures] $ time git log >/dev/null real 0m4.902s user 0m4.784s sys 0m0.120s [before] $ time git log --show-signature >/dev/null real 0m14.735s user 0m9.964s sys 0m0.944s [after] $ time git log --show-signature >/dev/null real 0m9.981s user 0m5.260s sys 0m0.936s Note that our user CPU time drops almost in half, close to the non-signature case, but we do still spend more wall-clock and system time, presumably from dealing with gpg. An alternative to this is to note that most commits do not have signatures (less than 1% in this repo), yet we pay the re-parsing cost for every commit just to find out if it has a mergetag or signature. If we checked that when parsing the commit initially, we could avoid re-examining most commits later on. Even if we did pursue that direction, however, this would still speed up the cases where we _do_ have signatures. So it's probably worth doing either way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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quote.h
#ifndef QUOTE_H
#define QUOTE_H
struct strbuf;
/* Help to copy the thing properly quoted for the shell safety.
* any single quote is replaced with '\'', any exclamation point
* is replaced with '\!', and the whole thing is enclosed in a
* single quote pair.
*
* For example, if you are passing the result to system() as an
* argument:
*
* sprintf(cmd, "foobar %s %s", sq_quote(arg0), sq_quote(arg1))
*
* would be appropriate. If the system() is going to call ssh to
* run the command on the other side:
*
* sprintf(cmd, "git-diff-tree %s %s", sq_quote(arg0), sq_quote(arg1));
* sprintf(rcmd, "ssh %s %s", sq_quote(host), sq_quote(cmd));
*
* Note that the above examples leak memory! Remember to free result from
* sq_quote() in a real application.
*
* sq_quote_buf() writes to an existing buffer of specified size; it
* will return the number of characters that would have been written
* excluding the final null regardless of the buffer size.
*/
extern void sq_quote_buf(struct strbuf *, const char *src);
extern void sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
/* This unwraps what sq_quote() produces in place, but returns
* NULL if the input does not look like what sq_quote would have
* produced.
*/
extern char *sq_dequote(char *);
/*
* Same as the above, but can be used to unwrap many arguments in the
* same string separated by space. Like sq_quote, it works in place,
* modifying arg and appending pointers into it to argv.
*/
extern int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc);
/*
* Same as above, but store the unquoted strings in an argv_array. We will
* still modify arg in place, but unlike sq_dequote_to_argv, the argv_array
* will duplicate and take ownership of the strings.
*/
struct argv_array;
extern int sq_dequote_to_argv_array(char *arg, struct argv_array *);
extern int unquote_c_style(struct strbuf *, const char *quoted, const char **endp);
extern size_t quote_c_style(const char *name, struct strbuf *, FILE *, int no_dq);
extern void quote_two_c_style(struct strbuf *, const char *, const char *, int);
extern void write_name_quoted(const char *name, FILE *, int terminator);
extern void write_name_quotedpfx(const char *pfx, size_t pfxlen,
const char *name, FILE *, int terminator);
extern void write_name_quoted_relative(const char *name, const char *prefix,
FILE *fp, int terminator);
/* quote path as relative to the given prefix */
extern char *quote_path_relative(const char *in, const char *prefix,
struct strbuf *out);
/* quoting as a string literal for other languages */
extern void perl_quote_buf(struct strbuf *sb, const char *src);
extern void python_quote_buf(struct strbuf *sb, const char *src);
extern void tcl_quote_buf(struct strbuf *sb, const char *src);
#endif
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