sapling/eden/fs/testharness/HgRepo.cpp

/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This software may be used and distributed according to the terms of the
 * GNU General Public License version 2.
 */

#include "eden/fs/testharness/HgRepo.h"

#include <folly/Exception.h>
#include <folly/File.h>
#include <folly/FileUtil.h>
#include <folly/String.h>
#include <folly/Subprocess.h>
#include <folly/logging/xlog.h>
#include <sys/stat.h>
#include <unistd.h>

#include "eden/fs/model/Hash.h"

using folly::StringPiece;
using folly::Subprocess;
using std::string;
using std::vector;

namespace facebook {
namespace eden {

namespace {
AbsolutePath findHgBinary() {
  auto hgPath = getenv("EDEN_HG_BINARY");
  if (hgPath) {
    return realpath(hgPath);
  }

  // Search through $PATH if $EDEN_HG_BINARY was not explicitly specified
  auto pathPtr = getenv("PATH");
  if (!pathPtr) {
    throw std::runtime_error("unable to find hg command: no PATH");
  }
  StringPiece pathEnv{pathPtr};
  vector<string> pathEnvParts;
  folly::split(":", pathEnv, pathEnvParts);

  for (const auto& dir : pathEnvParts) {
    for (const auto& name : {"hg.real", "hg"}) {
      auto exePath = folly::to<string>(dir, "/", name);
      XLOG(DBG5) << "Checking for hg at " << exePath;
      if (access(exePath.c_str(), X_OK) == 0) {
        return realpath(exePath);
      }
    }
  }

  throw std::runtime_error("unable to find hg in PATH");
}
} // namespace

HgRepo::HgRepo(AbsolutePathPiece path) : path_{path} {
  hgCmd_ = findHgBinary();
  XLOG(DBG1) << "Using hg command: " << hgCmd_;

  // Set up hgEnv_
  std::vector<const char*> passthroughVars{
      {"HG_REAL_BIN", "LLVM_PROFILE_FILE", "PATH"}};
  for (const char* varName : passthroughVars) {
    auto value = getenv(varName);
    if (value) {
      hgEnv_.push_back(folly::to<string>(varName, "=", value));
    }
  }
  hgEnv_.push_back("HGPLAIN=1");
  hgEnv_.push_back("HGRCPATH=");
  hgEnv_.push_back("CHGDISABLE=1");
  hgEnv_.push_back("NOSCMLOG=1");
  hgEnv_.push_back("LOCALE=C");
}

string HgRepo::hg(vector<string> args) {
  auto process = invokeHg(std::move(args));
  const auto outputs{process.communicate()};
  process.waitChecked();
  return outputs.first;
}

Subprocess HgRepo::invokeHg(vector<string> args) {
  return invokeHg(
      std::move(args), Subprocess::Options().chdir(path_.value()).pipeStdout());
}

Subprocess HgRepo::invokeHg(
    vector<string> args,
    const Subprocess::Options& options) {
  args.insert(args.begin(), "hg");

  XLOG(DBG1) << "repo " << path_ << " running: " << folly::join(" ", args);
  return Subprocess(args, options, hgCmd_.value().c_str(), &hgEnv_);
}

void HgRepo::hgInit(std::vector<std::string> extraArgs) {
  XLOG(DBG1) << "creating new hg repository at " << path_;

  // Invoke Subprocess directly here rather than using our hg() helper
  // function.  The hg() function requires the repository directory to already
  // exist.
  std::vector<std::string> args = {"hg", "init", path_.value()};
  args.insert(args.end(), extraArgs.begin(), extraArgs.end());
  Subprocess p(args, Subprocess::Options(), hgCmd_.value().c_str(), &hgEnv_);
  p.waitChecked();
}

void HgRepo::enableTreeManifest(AbsolutePathPiece cacheDirectory) {
  appendToHgrc(
      "[extensions]\n"
      "remotefilelog =\n"
      "treemanifest =\n"
      "[treemanifest]\n"
      "treeonly = true\n"
      "[remotefilelog]\n"
      "reponame = test\n"
      "cachepath = " +
      cacheDirectory.value().str() + "\n");
}

void HgRepo::cloneFrom(
    StringPiece serverRepoUrl,
    std::vector<std::string> extraArgs) {
  XLOG(DBG1) << "cloning new hg repository at " << path_ << " from "
             << serverRepoUrl;

  std::vector<std::string> args = {"hg", "clone"};
  args.insert(args.end(), extraArgs.begin(), extraArgs.end());
  args.push_back(serverRepoUrl.str());
  args.push_back(path_.value());
  XLOG(DBG1) << "running: " << folly::join(" ", args);

  Subprocess p(args, Subprocess::Options(), hgCmd_.value().c_str(), &hgEnv_);
  p.waitChecked();
}

void HgRepo::appendToHgrc(folly::StringPiece data) {
  auto hgrcPath = path_ + ".hg"_pc + "hgrc"_pc;
  folly::File hgrc{hgrcPath.stringPiece(), O_WRONLY | O_APPEND | O_CREAT};
  if (folly::writeFull(hgrc.fd(), data.data(), data.size()) < 0) {
    folly::throwSystemError("error writing to ", hgrcPath);
  }
}

void HgRepo::appendToHgrc(const std::vector<std::string>& lines) {
  appendToHgrc(folly::join("\n", lines) + "\n");
}

Hash HgRepo::commit(StringPiece message) {
  hg("commit",
     "-u",
     "Test User <user@example.com>",
     "-d",
     "2017-01-01 13:00:00",
     "-m",
     message.str());
  auto output = hg("log", "-r.", "-T{node}\\n");
  return Hash{folly::rtrimWhitespace(output)};
}

Hash HgRepo::getManifestForCommit(Hash commit) {
  auto output = hg("log", "-r", commit.toString(), "-T{manifest}\\n");
  return Hash{folly::rtrimWhitespace(output)};
}

void HgRepo::mkdir(RelativePathPiece path, mode_t permissions) {
  auto fullPath = path_ + path;
  auto rc = ::mkdir(fullPath.value().c_str(), permissions);
  folly::checkUnixError(rc, "mkdir ", fullPath);
}

void HgRepo::writeFile(
    RelativePathPiece path,
    StringPiece contents,
    mode_t permissions) {
  auto fullPath = path_ + path;
  folly::writeFileAtomic(fullPath.value(), contents, permissions);
}

void HgRepo::symlink(StringPiece contents, RelativePathPiece path) {
  auto fullPath = path_ + path;
  auto rc = ::symlink(contents.str().c_str(), fullPath.value().c_str());
  checkUnixError(rc, "error creating symlink at ", path);
}
} // namespace eden
} // namespace facebook