/*

* libgit2 "blame" example - shows how to use the blame API

*

* Written by the libgit2 contributors

*

* To the extent possible under law, the author(s) have dedicated all copyright

* and related and neighboring rights to this software to the public domain

* worldwide. This software is distributed without any warranty.

*

* You should have received a copy of the CC0 Public Domain Dedication along

* with this software. If not, see

* <http://creativecommons.org/publicdomain/zero/1.0/>.

*/

#include "git2cpp/repo.h"

#include "git2cpp/initializer.h"

#include "git2/blame.h"

#ifdef _MSC_VER

#define snprintf sprintf_s

#define strcasecmp strcmpi

#endif

/**

* This example demonstrates how to invoke the libgit2 blame API to roughly

* simulate the output of `git blame` and a few of its command line arguments.

*/

struct opts {

const char * path;

const char * commitspec = nullptr;

int start_line;

int end_line;

bool C = false;

bool M = false;

bool F = false;

opts(int argc, char *argv[]);

};

int main(int argc, char *argv[])

{

opts o(argc, argv);

git_blame_options blameopts = GIT_BLAME_OPTIONS_INIT;

if (o.M) blameopts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES;

if (o.C) blameopts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES;

if (o.F) blameopts.flags |= GIT_BLAME_FIRST_PARENT;

auto_git_initializer;

git::Repository repo(".");

/**

* The commit range comes in "commitish" form. Use the rev-parse API to

* nail down the end points.

*/

if (o.commitspec)

{

auto revspec = repo.revparse(o.commitspec);

if (revspec.flags() & GIT_REVSPEC_SINGLE)

{

blameopts.newest_commit = revspec.single()->id();

}

else

{

auto const & range = *revspec.range();

blameopts.oldest_commit = range.from.id();

blameopts.newest_commit = range.to.id();

}

}

/** Run the blame. */

auto blame = repo.blame_file(o.path, blameopts);

/**

* Get the raw data inside the blob for output. We use the

* `commitish:path/to/file.txt` format to find it.

*/

std::string spec = git_oid_is_zero(&blameopts.newest_commit)

? "HEAD"

: git::id_to_str(blameopts.newest_commit);

spec += ":";

spec += o.path;

auto blob = repo.blob_lookup(repo.revparse_single(spec.c_str()).single()->id());

char const * rawdata = reinterpret_cast<char const *>(blob.content());

size_t rawsize = blob.size();

/** Produce the output. */

size_t line = 1;

bool break_on_null_hunk = false;

for (size_t i = 0; i < rawsize; ++line) {

const git_blame_hunk *hunk = blame.hunk_byline(line);

if (break_on_null_hunk && !hunk)

break;

char const * eol = reinterpret_cast<char const *>(memchr(rawdata + i, '\n', rawsize - i));

if (hunk) {

break_on_null_hunk = true;

char oid[10] = {0};

git_oid_tostr(oid, 10, &hunk->final_commit_id);

char sig[128] = {0};

snprintf(sig, 127, "%s <%s>", hunk->final_signature->name, hunk->final_signature->email);

printf("%s ( %-30s %3d) %.*s\n",

oid,

sig,

(int)line,

(int)(eol - rawdata - i),

rawdata + i);

}

i = eol - rawdata + 1;

}

return 0;

}

/** Tell the user how to make this thing work. */

static void usage(const char *msg)

{

if (msg)

fprintf(stderr, "%s\n", msg);

fprintf(stderr, "usage: blame [options] [<commit range>] <path>\n");

fprintf(stderr, "\n");

fprintf(stderr, " <commit range> example: `HEAD~10..HEAD`, or `1234abcd`\n");

fprintf(stderr, " -L <n,m> process only line range n-m, counting from 1\n");

fprintf(stderr, " -M find line moves within and across files\n");

fprintf(stderr, " -C find line copies within and across files\n");

fprintf(stderr, " -F follow only the first parent commits\n");

fprintf(stderr, "\n");

exit(1);

}

/** Parse the arguments. */

opts::opts(int argc, char *argv[])

{

int i;

const char * bare_args[3] = {};

if (argc < 2) usage(nullptr);

for (i=1; i<argc; i++) {

char *a = argv[i];

if (a[0] != '-') {

int i=0;

while (bare_args[i] && i < 3) ++i;

if (i >= 3)

usage("Invalid argument set");

bare_args[i] = a;

}

else if (!strcmp(a, "--"))

continue;

else if (!strcasecmp(a, "-M"))

M = true;

else if (!strcasecmp(a, "-C"))

C = true;

else if (!strcasecmp(a, "-F"))

F = true;

else if (!strcasecmp(a, "-L")) {

i++; a = argv[i];

if (i >= argc) throw std::runtime_error("Not enough arguments to -L");

if (sscanf(a, "%d,%d", &start_line, &end_line) != 2)

{

fprintf(stderr, "-L format error\n");

std::abort();

}

}

else {

/* commit range */

if (commitspec) throw std::runtime_error("Only one commit spec allowed");

commitspec = a;

}

}

/* Handle the bare arguments */

if (!bare_args[0]) usage("Please specify a path");

path = bare_args[0];

if (bare_args[1]) {

/* <commitspec> <path> */

path = bare_args[1];

commitspec = bare_args[0];

}

if (bare_args[2]) {

/* <oldcommit> <newcommit> <path> */

char spec[128] = {0};

path = bare_args[2];

sprintf(spec, "%s..%s", bare_args[0], bare_args[1]);

commitspec = spec;

}

}