Git Class Reference

Git utility class for browsing git archives. More...

#include <Git.h>

Classes
class	Exception
	Exception class. More...
struct	Object
	Git object. More...
class	ObjectId
	Git object Id. More...

Public Types
enum	ObjectType { Tree, Commit, Blob }
	Git object type. More...
typedef std::list< std::pair< std::string, std::string > >	Cache

Public Member Functions
	Git ()
	Constructor. More...
void	setRepositoryPath (const std::string &repository)
	Set the git repository path. More...
ObjectId	getCommitTree (const std::string &revision) const
	Get the tree for a particular revision. More...
ObjectId	getCommit (const std::string &revision) const
	Get the commit for a particular revision. More...
ObjectId	getTreeFromCommit (const ObjectId &commit) const
	Get the tree for a particular commit. More...
Object	treeGetObject (const ObjectId &tree, int index) const
	Get some info on a tree object. More...
int	treeSize (const ObjectId &tree) const
	Return the number of objects inside a tree object. More...
std::string	catFile (const ObjectId &id) const
	Return the raw contents of a git object. More...

Private Member Functions
std::string	baseCmd () const
	The git base command after which extra arguments are added. More...
void	checkRepository () const
	Checks the repository. More...
bool	getCmdResult (const std::string &cmd, std::string &result, const std::string &tag) const
	Returns a line identified by a tag from the output of a git command. More...
bool	getCmdResult (const std::string &cmd, std::string &result, int index) const
	Returns the ith line from the output of a git command. More...
int	getCmdResultLineCount (const std::string &cmd) const
	Returns the number of lines in the output of a git command. More...

Private Attributes
bool	is_bare_
	Whether the repositoy is a bare repository. More...
std::string	repository_
	The path to the repository. More...
Cache	cache_
	A small LRU cache that stores results of git commands. More...

Detailed Description

Git utility class for browsing git archives.

Far from complete! Only browses git revisions.

Definition at line 24 of file Git.h.

Member Typedef Documentation

typedef std::list<std::pair<std::string, std::string> > Git::Cache

Definition at line 120 of file Git.h.

Member Enumeration Documentation

enum Git::ObjectType

Git object type.

Enumerator
Tree
Commit
Blob

Definition at line 59 of file Git.h.

{ Tree, Commit, Blob };

Constructor & Destructor Documentation

Git::Git

(

)

Constructor.

Definition at line 201 of file Git.C.

  : is_bare_(false),
    cache_(3) // cache of 3 git results
{ }

Member Function Documentation

std::string Git::baseCmd ( ) const

private

The git base command after which extra arguments are added.

Definition at line 292 of file Git.C.

{
  if (is_bare_)
    return "git --git-dir=" + repository_;
  else
    return "git --git-dir=" + repository_ + "/.git"
           " --work-tree=" + repository_;
}

std::string Git::catFile

(

const ObjectId &

id

)

const

Return the raw contents of a git object.

Exceptions

Exception

: in case of a git error.

Definition at line 221 of file Git.C.

{
  std::string result;

  if (!getCmdResult("cat-file -p " + id.toString(), result, -1))
    throw Exception("Git: could not cat '" + id.toString() + "'");

  return result;
}

void Git::checkRepository ( ) const

private

Checks the repository.

Exceptions

Exception

: in case the repository is not a valid.

Definition at line 359 of file Git.C.

{
  POpenWrapper p(baseCmd() + " branch", cache_);

  std::string r;
  if (p.exitStatus() != 0)
    throw Exception("Git error: " + p.readLine(r));
}

bool Git::getCmdResult ( const std::string &  cmd, std::string &  result, const std::string &  tag  ) const

private

Returns a line identified by a tag from the output of a git command.

The line is filled in result. Returns whether a line starting with tag could be found.

Exceptions

Exception

: in case the command failed

Definition at line 324 of file Git.C.

{
  POpenWrapper p(baseCmd() + " " + gitCmd, cache_);

  if (p.exitStatus() != 0)
    throw Exception("Git error: " + p.readLine(result));

  while (!p.finished()) {
    p.readLine(result);
    if (boost::starts_with(result, tag))
      return true;
  }

  return false;
}

bool Git::getCmdResult ( const std::string &  cmd, std::string &  result, int  index  ) const

private

Returns the ith line from the output of a git command.

The line is filled in result. Returns the whole git output if index = -1, otherwise the line with line number index.

Exceptions

Exception

: in case the command failed

Definition at line 301 of file Git.C.

{
  POpenWrapper p(baseCmd() + " " + gitCmd, cache_);

  if (p.exitStatus() != 0)
    throw Exception("Git error: " + p.readLine(result));

  if (index == -1) {
    result = p.contents();
    return true;
  } else
    p.readLine(result);

  for (int i = 0; i < index; ++i) {
    if (p.finished())
      return false;
    p.readLine(result);
  }

  return true;
}

int Git::getCmdResultLineCount ( const std::string &  cmd ) const

private

Returns the number of lines in the output of a git command.

Exceptions

Exception

: in case the command failed

Definition at line 341 of file Git.C.

{
  POpenWrapper p(baseCmd() + " " + gitCmd, cache_);

  std::string r;

  if (p.exitStatus() != 0)
    throw Exception("Git error: " + p.readLine(r));

  int result = 0;
  while (!p.finished()) {
    p.readLine(r);
    ++result;
  }

  return result;
}

Git::ObjectId Git::getCommit

(

const std::string &

revision

)

const

Get the commit for a particular revision.

Exceptions

Exception

: in case of a git error.

Definition at line 231 of file Git.C.

{
  std::string sha1Commit;
  getCmdResult("rev-parse " + revision, sha1Commit, 0);
  return ObjectId(sha1Commit);
}

Git::ObjectId Git::getCommitTree

(

const std::string &

revision

)

const

Get the tree for a particular revision.

Exceptions

Exception

: in case of a git error.

Definition at line 215 of file Git.C.

{
  Git::ObjectId commit = getCommit(revision);
  return getTreeFromCommit(commit);
}

Git::ObjectId Git::getTreeFromCommit

(

const ObjectId &

commit

)

const

Get the tree for a particular commit.

Exceptions

Exception

: in case of a git error.

Definition at line 238 of file Git.C.

{
  std::string treeLine;
  if (!getCmdResult("cat-file -p " + commit.toString(), treeLine, "tree"))
    throw Exception("Git: could not parse tree from commit '" 
                    + commit.toString() + "'");

  std::vector<std::string> v;
  boost::split(v, treeLine, boost::is_any_of(" "));
  if (v.size() != 2)
    throw Exception("Git: could not parse tree from commit '"
                    + commit.toString() + "': '" + treeLine + "'");
  return ObjectId(v[1]);
}

void Git::setRepositoryPath

(

const std::string &

repository

)

Set the git repository path.

Exceptions

Exception

: if the path does not specify a valid repository.

Definition at line 206 of file Git.C.

{ 
  struct stat sb;
  is_bare_ = !(stat((repositoryPath + "/.git").c_str(), &sb) == 0 &&
               S_ISDIR(sb.st_mode));
  repository_ = repositoryPath;
  checkRepository();
}

Git::Object Git::treeGetObject	(	const ObjectId &	tree,
		int	index
	)		const

Get some info on a tree object.

The object is specified based on its index in the parent tree object.

Exceptions

Exception

: in case of a git error.

Definition at line 253 of file Git.C.

{
  std::string objectLine;
  if (!getCmdResult("cat-file -p " + tree.toString(), objectLine, index))
    throw Exception("Git: could not read object %"
                    + asString(index).toUTF8()
                    + "  from tree " + tree.toString());
  else {
    std::vector<std::string> v1, v2;
    boost::split(v1, objectLine, boost::is_any_of("\t"));
    if (v1.size() != 2)
      throw Exception("Git: could not parse tree object line: '"
                      + objectLine + "'");
    boost::split(v2, v1[0], boost::is_any_of(" "));
    if (v2.size() != 3)
      throw Exception("Git: could not parse tree object line: '"
                      + objectLine + "'");
 
    const std::string& stype = v2[1];
    ObjectType type;
    if (stype == "tree")
      type = Tree;
    else if (stype == "blob")
      type = Blob;
    else
      throw Exception("Git: Unknown type: " + stype);

    Git::Object result(ObjectId(v2[2]), type);
    result.name = v1[1];

    return result;
  }
}

int Git::treeSize

(

const ObjectId &

tree

)

const

Return the number of objects inside a tree object.

Exceptions

Exception

: in case of a git error.

Definition at line 287 of file Git.C.

{
  return getCmdResultLineCount("cat-file -p " + tree.toString());
}

Member Data Documentation

Cache Git::cache_

mutableprivate

A small LRU cache that stores results of git commands.

Definition at line 137 of file Git.h.

bool Git::is_bare_

private

Whether the repositoy is a bare repository.

Definition at line 129 of file Git.h.

std::string Git::repository_

private

The path to the repository.

Definition at line 133 of file Git.h.

---

The documentation for this class was generated from the following files:

• /home/roel/project/wt/public-git/wt/examples/gitmodel/Git.h
• /home/roel/project/wt/public-git/wt/examples/gitmodel/Git.C