// Copyright 2019 Roman Perepelitsa.
//
// This file is part of GitStatus.
//
// GitStatus is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GitStatus is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with GitStatus. If not, see <https://www.gnu.org/licenses/>.
#include "repo.h"
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <algorithm>
#include <atomic>
#include <cstdlib>
#include <cstring>
#include <exception>
#include <iterator>
#include <memory>
#include <type_traits>
#include <utility>
#include "arena.h"
#include "check.h"
#include "check_dir_mtime.h"
#include "dir.h"
#include "git.h"
#include "print.h"
#include "scope_guard.h"
#include "stat.h"
#include "string_cmp.h"
#include "thread_pool.h"
#include "timer.h"
namespace gitstatus {
namespace {
using namespace std::string_literals;
template <class T>
T Load(const std::atomic<T>& x) {
return x.load(std::memory_order_relaxed);
}
template <class T>
void Store(std::atomic<T>& x, T v) {
x.store(v, std::memory_order_relaxed);
}
template <class T>
T Inc(std::atomic<T>& x, T by = 1) {
return x.fetch_add(by, std::memory_order_relaxed);
}
template <class T>
T Dec(std::atomic<T>& x) {
return x.fetch_sub(1, std::memory_order_relaxed);
}
template <class T>
T Exchange(std::atomic<T>& x, T v) {
return x.exchange(v, std::memory_order_relaxed);
}
const char* DeltaStr(git_delta_t t) {
switch (t) {
case GIT_DELTA_UNMODIFIED: return "unmodified";
case GIT_DELTA_ADDED: return "added";
case GIT_DELTA_DELETED: return "deleted";
case GIT_DELTA_MODIFIED: return "modified";
case GIT_DELTA_RENAMED: return "renamed";
case GIT_DELTA_COPIED: return "copied";
case GIT_DELTA_IGNORED: return "ignored";
case GIT_DELTA_UNTRACKED: return "untracked";
case GIT_DELTA_TYPECHANGE: return "typechange";
case GIT_DELTA_UNREADABLE: return "unreadable";
case GIT_DELTA_CONFLICTED: return "conflicted";
}
return "unknown";
}
} // namespace
bool Repo::Shard::Contains(Str<> str, StringView path) const {
if (str.Lt(path, start_s)) return false;
if (end_s.empty()) return true;
path.len = std::min(path.len, end_s.size());
return !str.Lt(end_s, path);
}
Repo::Repo(git_repository* repo, Limits lim) : lim_(std::move(lim)), repo_(repo), tag_db_(repo) {
if (lim_.max_num_untracked) {
GlobalThreadPool()->Schedule([this] {
bool check = CheckDirMtime(git_repository_path(repo_));
std::unique_lock<std::mutex> lock(mutex_);
CHECK(Load(untracked_cache_) == Tribool::kUnknown);
Store(untracked_cache_, check ? Tribool::kTrue : Tribool::kFalse);
cv_.notify_one();
});
} else {
untracked_cache_ = Tribool::kFalse;
}
}
Repo::~Repo() {
{
std::unique_lock<std::mutex> lock(mutex_);
while (untracked_cache_ == Tribool::kUnknown) cv_.wait(lock);
}
if (git_index_) git_index_free(git_index_);
git_repository_free(repo_);
}
IndexStats Repo::GetIndexStats(const git_oid* head, git_config* cfg) {
ON_SCOPE_EXIT(this, orig_lim = lim_) { lim_ = orig_lim; };
auto Off = [&](const char* name) {
int val;
if (git_config_get_bool(&val, cfg, name) || val) return false;
LOG(INFO) << "Honoring git config option: " << name << " = false";
return true;
};
if (!lim_.ignore_status_show_untracked_files && Off("status.showUntrackedFiles")) {
lim_.max_num_untracked = 0;
}
if (!lim_.ignore_bash_show_untracked_files && Off("bash.showUntrackedFiles")) {
lim_.max_num_untracked = 0;
}
if (!lim_.ignore_bash_show_dirty_state && Off("bash.showDirtyState")) {
lim_.max_num_staged = 0;
lim_.max_num_unstaged = 0;
lim_.max_num_conflicted = 0;
}
if (git_index_) {
int new_index;
VERIFY(!git_index_read_ex(git_index_, 0, &new_index)) << GitError();
if (new_index) {
head_ = {};
index_.reset();
}
} else {
VERIFY(!git_repository_index(&git_index_, repo_)) << GitError();
// Query an attribute (doesn't matter which) to initialize repo's attribute
// cache. It's a workaround for synchronization bugs (data races) in libgit2
// that result from lazy cache initialization without synchronization.
// Thankfully, subsequent cache reads and writes are properly synchronized.
const char* attr;
VERIFY(!git_attr_get(&attr, repo_, 0, "x", "x")) << GitError();
}
UpdateShards();
Store(error_, false);
Store(unstaged_, {});
Store(untracked_, {});
Store(unstaged_deleted_, {});
std::vector<const char*> dirty_candidates;
const size_t index_size = git_index_entrycount(git_index_);
if (!lim_.max_num_staged && !lim_.max_num_conflicted) {
head_ = {};
Store(staged_, {});
Store(conflicted_, {});
Store(staged_new_, {});
Store(staged_deleted_, {});
Store(skip_worktree_, {});
Store(assume_unchanged_, {});
} else if (head) {
if (git_oid_equal(head, &head_)) {
LOG(INFO) << "Index and HEAD unchanged; staged = " << Load(staged_)
<< ", conflicted = " << Load(conflicted_);
} else {
head_ = *head;
Store(staged_, {});
Store(conflicted_, {});
Store(staged_new_, {});
Store(staged_deleted_, {});
Store(skip_worktree_, {});
Store(assume_unchanged_, {});
StartStagedScan(head);
}
} else {
head_ = {};
size_t staged = 0;
size_t skip_worktree = 0;
size_t assume_unchanged = 0;
for (size_t i = 0; i != index_size; ++i) {
const git_index_entry* entry = git_index_get_byindex_no_sort(git_index_, i);
if (!(entry->flags_extended & GIT_INDEX_ENTRY_INTENT_TO_ADD)) ++staged;
if (entry->flags_extended & GIT_INDEX_ENTRY_SKIP_WORKTREE) ++skip_worktree;
if (entry->flags & GIT_INDEX_ENTRY_VALID) ++assume_unchanged;
}
Store(staged_, staged);
Store(conflicted_, {});
Store(staged_new_, staged);
Store(staged_deleted_, {});
Store(skip_worktree_, skip_worktree);
Store(assume_unchanged_, assume_unchanged);
}
if (index_size <= lim_.dirty_max_index_size &&
(lim_.max_num_unstaged || lim_.max_num_untracked)) {
if (!index_) index_ = std::make_unique<Index>(repo_, git_index_);
dirty_candidates = index_->GetDirtyCandidates({.include_untracked = lim_.max_num_untracked > 0,
.untracked_cache = Load(untracked_cache_)});
if (dirty_candidates.empty()) {
LOG(INFO) << "Clean repo: no dirty candidates";
} else {
LOG(INFO) << "Found " << dirty_candidates.size() << " dirty candidate(s) spanning from "
<< Print(dirty_candidates.front()) << " to " << Print(dirty_candidates.back());
}
StartDirtyScan(dirty_candidates);
}
Wait();
VERIFY(!Load(error_));
size_t num_staged = std::min(Load(staged_), lim_.max_num_staged);
size_t num_unstaged = std::min(Load(unstaged_), lim_.max_num_unstaged);
return {.index_size = index_size,
.num_staged = num_staged,
.num_unstaged = num_unstaged,
.num_conflicted = std::min(Load(conflicted_), lim_.max_num_conflicted),
.num_untracked = std::min(Load(untracked_), lim_.max_num_untracked),
.num_staged_new = std::min(Load(staged_new_), num_staged),
.num_staged_deleted = std::min(Load(staged_deleted_), num_staged),
.num_unstaged_deleted = std::min(Load(unstaged_deleted_), num_unstaged),
.num_skip_worktree = Load(skip_worktree_),
.num_assume_unchanged = Load(assume_unchanged_)};
}
int Repo::OnDelta(const char* type, const git_diff_delta& d, std::atomic<size_t>& c1, size_t m1,
const std::atomic<size_t>& c2, size_t m2) {
auto Msg = [&]() {
const char* status = DeltaStr(d.status);
std::ostringstream strm;
strm << "Found " << type << " file";
if (strcmp(status, type)) strm << " (" << status << ")";
strm << ": " << Print(d.new_file.path);
return strm.str();
};
size_t v = Inc(c1);
if (v) {
LOG(DEBUG) << Msg();
} else {
LOG(INFO) << Msg();
}
if (v + 1 < m1) return GIT_DIFF_DELTA_DO_NOT_INSERT;
if (Load(c2) < m2) return GIT_DIFF_DELTA_DO_NOT_INSERT | GIT_DIFF_DELTA_SKIP_TYPE;
return GIT_EUSER;
}
void Repo::StartDirtyScan(const std::vector<const char*>& paths) {
if (paths.empty()) return;
git_diff_options opt = GIT_DIFF_OPTIONS_INIT;
opt.payload = this;
opt.flags = GIT_DIFF_INCLUDE_TYPECHANGE_TREES | GIT_DIFF_SKIP_BINARY_CHECK |
GIT_DIFF_DISABLE_PATHSPEC_MATCH | GIT_DIFF_EXEMPLARS;
if (lim_.max_num_untracked) {
opt.flags |= GIT_DIFF_INCLUDE_UNTRACKED;
if (lim_.recurse_untracked_dirs) opt.flags |= GIT_DIFF_RECURSE_UNTRACKED_DIRS;
} else {
opt.flags |= GIT_DIFF_ENABLE_FAST_UNTRACKED_DIRS;
}
opt.ignore_submodules = GIT_SUBMODULE_IGNORE_DIRTY;
opt.notify_cb = +[](const git_diff* diff, const git_diff_delta* delta,
const char* matched_pathspec, void* payload) -> int {
if (delta->status == GIT_DELTA_CONFLICTED) return GIT_DIFF_DELTA_DO_NOT_INSERT;
Repo* repo = static_cast<Repo*>(payload);
if (Load(repo->error_)) return GIT_EUSER;
if (delta->status == GIT_DELTA_UNTRACKED) {
return repo->OnDelta("untracked", *delta, repo->untracked_, repo->lim_.max_num_untracked,
repo->unstaged_, repo->lim_.max_num_unstaged);
} else {
if (delta->status == GIT_DELTA_DELETED) Inc(repo->unstaged_deleted_);
return repo->OnDelta("unstaged", *delta, repo->unstaged_, repo->lim_.max_num_unstaged,
repo->untracked_, repo->lim_.max_num_untracked);
}
};
const Str<> str(git_index_is_case_sensitive(git_index_));
auto shard = shards_.begin();
for (auto p = paths.begin(); p != paths.end();) {
opt.range_start = *p;
opt.range_end = *p;
opt.pathspec.strings = const_cast<char**>(&*p);
opt.pathspec.count = 1;
while (!shard->Contains(str, StringView(*p))) ++shard;
while (++p != paths.end() && shard->Contains(str, StringView(*p))) {
opt.range_end = *p;
++opt.pathspec.count;
}
RunAsync([this, opt]() {
git_diff* diff = nullptr;
LOG(DEBUG) << "git_diff_index_to_workdir from " << Print(opt.range_start) << " to "
<< Print(opt.range_end);
switch (git_diff_index_to_workdir(&diff, repo_, git_index_, &opt)) {
case 0:
git_diff_free(diff);
break;
case GIT_EUSER:
break;
default:
LOG(ERROR) << "git_diff_index_to_workdir: " << GitError();
throw Exception();
}
});
}
}
void Repo::StartStagedScan(const git_oid* head) {
git_commit* commit = nullptr;
VERIFY(!git_commit_lookup(&commit, repo_, head)) << GitError();
ON_SCOPE_EXIT(=) { git_commit_free(commit); };
git_tree* tree = nullptr;
VERIFY(!git_commit_tree(&tree, commit)) << GitError();
git_diff_options opt = GIT_DIFF_OPTIONS_INIT;
opt.flags = GIT_DIFF_EXEMPLARS | GIT_DIFF_INCLUDE_TYPECHANGE_TREES;
opt.payload = this;
opt.notify_cb = +[](const git_diff* diff, const git_diff_delta* delta,
const char* matched_pathspec, void* payload) -> int {
Repo* repo = static_cast<Repo*>(payload);
if (Load(repo->error_)) return GIT_EUSER;
if (delta->status == GIT_DELTA_CONFLICTED) {
return repo->OnDelta("conflicted", *delta, repo->conflicted_, repo->lim_.max_num_conflicted,
repo->staged_, repo->lim_.max_num_staged);
} else {
if (delta->status == GIT_DELTA_ADDED) Inc(repo->staged_new_);
if (delta->status == GIT_DELTA_DELETED) Inc(repo->staged_deleted_);
return repo->OnDelta("staged", *delta, repo->staged_, repo->lim_.max_num_staged,
repo->conflicted_, repo->lim_.max_num_conflicted);
}
};
for (const Shard& shard : shards_) {
RunAsync([this, tree, opt, shard]() mutable {
size_t skip_worktree = 0;
size_t assume_unchanged = 0;
for (size_t i = shard.start_i; i != shard.end_i; ++i) {
const git_index_entry* entry = git_index_get_byindex_no_sort(git_index_, i);
if (entry->flags_extended & GIT_INDEX_ENTRY_SKIP_WORKTREE) ++skip_worktree;
if (entry->flags & GIT_INDEX_ENTRY_VALID) ++assume_unchanged;
}
Inc(skip_worktree_, skip_worktree);
Inc(assume_unchanged_, assume_unchanged);
opt.range_start = shard.start_s.c_str();
opt.range_end = shard.end_s.c_str();
git_diff* diff = nullptr;
LOG(DEBUG) << "git_diff_tree_to_index from " << Print(opt.range_start) << " to "
<< Print(opt.range_end);
switch (git_diff_tree_to_index(&diff, repo_, tree, git_index_, &opt)) {
case 0:
git_diff_free(diff);
break;
case GIT_EUSER:
break;
default:
LOG(ERROR) << "git_diff_tree_to_index: " << GitError();
throw Exception();
}
});
}
}
void Repo::UpdateShards() {
constexpr size_t kEntriesPerShard = 512;
const Str<> str(git_index_is_case_sensitive(git_index_));
size_t index_size = git_index_entrycount(git_index_);
ON_SCOPE_EXIT(&) {
LOG(INFO) << "Splitting " << index_size << " object(s) into " << shards_.size() << " shard(s)";
};
if (index_size <= kEntriesPerShard || GlobalThreadPool()->num_threads() < 2) {
shards_ = {{
.start_s = "",
.end_s = "",
.start_i = 0,
.end_i = index_size}};
return;
}
size_t shards =
std::min(index_size / kEntriesPerShard + 1, 2 * GlobalThreadPool()->num_threads());
shards_.clear();
shards_.reserve(shards);
std::string last_s;
size_t last_i = 0;
for (size_t i = 0; i != shards - 1; ++i) {
size_t idx = (i + 1) * index_size / shards;
std::string split = git_index_get_byindex_no_sort(git_index_, idx)->path;
auto pos = split.find_last_of('/');
if (pos == std::string::npos) continue;
split = split.substr(0, pos + 1);
Shard shard;
shard.end_s = split;
--shard.end_s.back();
if (!str.Lt(last_s, shard.end_s)) continue;
shard.start_s = std::move(last_s);
last_s = std::move(split);
shard.start_i = last_i;
shard.end_i = idx;
last_i = idx;
shards_.push_back(std::move(shard));
}
shards_.push_back({
.start_s = std::move(last_s),
.end_s = "",
.start_i = last_i,
.end_i = index_size});
CHECK(!shards_.empty());
CHECK(shards_.size() <= shards);
CHECK(shards_.front().start_s.empty());
CHECK(shards_.front().start_i == 0);
CHECK(shards_.back().end_s.empty());
CHECK(shards_.back().end_i == index_size);
for (size_t i = 0; i != shards_.size(); ++i) {
if (i) {
const git_index_entry* entry = git_index_get_byindex_no_sort(git_index_, shards_[i].start_i);
CHECK(!std::memcmp(shards_[i].start_s.c_str(), entry->path, shards_[i].start_s.size()));
CHECK(str.Lt(shards_[i - 1].end_s, shards_[i].start_s));
CHECK(shards_[i - 1].end_i == shards_[i].start_i);
}
if (i != shards_.size() - 1) {
CHECK(shards_[i].start_i < shards_[i].end_i);
CHECK(str.Lt(shards_[i].start_s, shards_[i].end_s));
}
}
}
void Repo::DecInflight() {
std::unique_lock<std::mutex> lock(mutex_);
CHECK(Load(inflight_) > 0);
if (Dec(inflight_) == 1) cv_.notify_one();
}
void Repo::RunAsync(std::function<void()> f) {
Inc(inflight_);
try {
GlobalThreadPool()->Schedule([this, f = std::move(f)] {
try {
ON_SCOPE_EXIT(&) { DecInflight(); };
f();
} catch (const Exception&) {
if (!Load(error_)) {
std::unique_lock<std::mutex> lock(mutex_);
if (!Load(error_)) {
Store(error_, true);
cv_.notify_one();
}
}
}
});
} catch (...) {
DecInflight();
throw;
}
}
void Repo::Wait() {
std::unique_lock<std::mutex> lock(mutex_);
while (inflight_) cv_.wait(lock);
}
std::future<std::string> Repo::GetTagName(const git_oid* target) {
auto* promise = new std::promise<std::string>;
std::future<std::string> res = promise->get_future();
GlobalThreadPool()->Schedule([=] {
ON_SCOPE_EXIT(&) { delete promise; };
if (!target) {
promise->set_value("");
return;
}
try {
promise->set_value(tag_db_.TagForCommit(*target));
} catch (const Exception&) {
promise->set_exception(std::current_exception());
}
});
return res;
}
} // namespace gitstatus
