All initialization functions now return error codes instead of pointers.
Error codes are now properly propagated on most functions. Several new
and more specific error codes have been added in common.h

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Added -fPIC (position-independent code) to the EXTRA_CFLAGS var in the
Makefile. Required in x64 when building the shared library.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The constructor to git_repository is now called

	'git_repository_open(path)'

and takes a path to a git repository instead of an existing ODB object.
Unit tests have been updated accordingly and the two test repositories
have been merged into one.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Issue 9 on the tracker. The commit object getters for in-memory objects
were trying to parse an inexistant on-disk object when one of the commit
attributes which were still not set was queried.

We now return a NULL value when this happens.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Before changing the attributes of a commit, make sure that the internal
status is consistent with the one in the repository.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

You can know access the owning repository of any existing object, or the
repository on which a revision walker is working on.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Test the new method by loading all the objects in the sample ODB with a
full-read and a header-only read, and comparing the types and sizes.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

As requested, git_odb_read_header looks up an object on the ODB, but loads
only the header information (type & size) without loading any of the
actual file contents in memory.

It is significantly faster than doing a git_odb_read if you only need an
object's information and not its contents.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

String mememory is now managed in a much more sane manner.

Fixes include:

	- git_person email and name is no longer limited to 64 characters
	- git_tree_entry filename is no longer limited to 255 characters
	- raw objects are properly opened & closed the minimum amount of
	times required for parsing
	- unit tests no longer leak
	- removed 5 other misc memory leaks as reported by Valgrind
	- tree writeback no longer segfaults on rare ocassions

The git_person struct is no longer public. It is now managed by the
library, and getter methods are in place to access its internal
attributes.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

In particular, msvc complains thus:

    t0603-sort.c(23) : warning C4244: 'function' : conversion from \
        'time_t' to 'unsigned int', possible loss of data

Note that msvc, by default, defines time_t as a 64-bit type, whereas
srand() is expecting an (32-bit) unsigned int. In order to suppress
the warning, we simply cast the return value of the time() function
call to 'unsigned int'.

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>

Since commit 70aab459, the msvc and MinGW builds have relied on
the built-in implementation of ntohl() and htonl(), rather than
linking the wsock32 library. The new index manipulation code now
calls ntohs()/htons() in addition to ntohl()/htonl(), so we need
to provide a built-in implementation of the 16-bit functions.

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>

will generate documenation and not hide them.

Signed-off-by: Benjamin C Meyer <ben@meyerhome.net>

Signed-off-by: Benjamin C Meyer <ben@meyerhome.net>

Signed-off-by: Benjamin C Meyer <ben@meyerhome.net>

The tree array wasn't being initialized when instantiating a tree object
in memory instead of loading it from disk.

New unit tests added to check for the problem.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Basic write-back & in-memory editing for objects is now tested in t0403
(commits), t0802 (tags) and t0902 (trees).

Add new helper functions in test_helpers.c to remove the loose objects
created when doing write-back tests.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Tag files can now be created and modified in-memory (all the setter
methods have been implemented), and written back to disk using the
generic git_object_write() method.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

git_tree_entry_byname was dereferencing a NULL pointer when the searched
file couldn't be found on the tree.

New test cases have been added to check for entry access methods.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

All the setter methods for git_tree have been added, including the
setters for attributes on each git_tree_entry and methods to add/remove
entries of the tree.

Modified trees and trees created in-memory from scratch can be written
back to the repository using git_object_write().

Signed-off-by: Vicent Marti <tanoku@gmail.com>

All repository objects can now be created from scratch in memory using
either the git_object_new() method, or the corresponding git_XXX_new()
for each object.

So far, only git_commits can be written back to disk once created in
memory.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

All the required git_commit_set_XXX methods have been implemented; all
the attributes of a commit object can now be modified in-memory.

The new method git_object_write() automatically writes back the
in-memory changes of any object to the repository. So far it only
supports git_commit objects.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The new 'git__source_printf' does an overflow-safe printf on a source
bfufer.

The new 'git__source_write' does an overflow-safe byte write on a source
buffer.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The 'git_obj' structure is now called 'git_rawobj', since
it represents a raw object read from the ODB.

The 'git_repository_object' structure is now called 'git_object',
since it's the base object class for all objects.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

git_repository_object has now several internal methods to write back the
object information in the repository.

- git_repository__dbo_prepare_write()
	Prepares the DBO object to be modified

- git_repository__dbo_write()
	Writes new bytes to the DBO object

- git_repository__dbo_writeback()
	Writes back the changes to the repository

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Added several methods to access:

	- The ODB behind a repo
	- The SHA1 id behind a generic repo object
	- The type of a generic repo object

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Some compilers give linking problems when exporting 'uint32_t' as a
return type in the external API. Use generic types instead.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

A new method 'git_repository_object_free' allows to manually force the
freeing of a repository object, even though they are still automatically
managed by the repository and don't need to be freed by the user.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

All loaded objects through git_repository_lookup are properly parsed &
free'd on failure.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

New function in util.c to do a dump of a buffer's contents in
hexadecimal to stdout.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The interface for loading and parsing tree objects from a repository has
been completed with all the required accesor methods for attributes,
support for manipulating individual tree entries and a new unit test
t0901-readtree which tries to load and parse a tree object from a
repository.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Three new unit tests, t06XX files have been added.

	t0601-read: tests for loading index files from disk,
				for creating in-memory indexes and for accessing
				index entries.
	t0602-write: tests for writing index files back to disk
	t0603-sort: tests for properly sorting the entries array of an index

Two test indexes have been added in 'tests/resources/':

	test/resources/index: a sample index from a libgit2 repository

	test/resources/gitgit.index: a sample index from a git.git
		repository (includes TREE extension data)

Signed-off-by: Vicent Marti <tanoku@gmail.com>

All the external resources used by the tests are now placed inside the
common 'tests/resources' directory.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The new 'git_index' structure is an in-memory representation
of a git index on disk; the 'git_index_entry' structures represent
each one of the file entries on the index.

The following calls for index instantiation have been added:

	git_index_alloc(): instantiate a new index structure
	git_index_free(): free an existing index
	git_index_clear(): clear all the entires in an existing file

The following calls for index reading and writing have been added:

	git_index_read(): update the contents of the index structure from
					  its file on disk.

		Internally implemented through:
			git_index__parse()

	Index files are stored on disk in network byte order; all integer fields
	inside them are properly converted to the machine's byte order when
	loading them in memory. The parsing engine also distinguishes
	between normal index entries and extended entries with 2 extra bytes
	of flags.

	The 'TREE' extension for index entries is also loaded into memory:
	Tree caches stored in Index files are loaded into the
	'git_index_tree' structure pointed by the 'tree' pointer inside
	'git_index'.

	'index->tree' points to the root node of the tree cache; the full tree
	can be traversed through each of the node's 'tree->children'.

	Index files can be written back to disk through:

	git_index_write(): atomic writing of existing index objects
		backed by internal method git_index__write()

The following calls for entry manipulation have been added:

	git_index_add(): insert an empty entry to the index

	git_index_find(): search an entry by its path name

	git_index__append(): appends a new index entry to the end of the
						 list, resizing the entries array if required

	New index entries are always inserted at the end of the array; since the
	index entries must be sorted for it to be internally consistent, the
	index object is only sorted once, and if required, before accessing the
	whole entriea array (e.g. before writing to disk, before traversing,
	etc).

	git_index__remove_pos(): remove an index entry in a specific position

	git_index__sort(): sort the entries in the array by path name

	The entries array is sorted stably and in place using an
	insertion sort, which ought to be the most efficient approach
	since the entries array is always mostly-sorted.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The struct 'git_filelock' represents an atomically-locked
file, git-style.

Locked files can be modified atomically through the new file lock
interface:

int git_filelock_init(git_filelock *lock, const char *path);
int git_filelock_lock(git_filelock *lock, int append);
void git_filelock_unlock(git_filelock *lock);
int git_filelock_commit(git_filelock *lock);
int git_filelock_write(git_filelock *lock, const char *buffer, size_t length);

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The old 'git_revpool' object has been removed and
split into two distinct objects with separate
functionality, in order to have separate methods for
object management and object walking.

*	A new object 'git_repository' does the high-level
	management of a repository's objects (commits, trees,
	tags, etc) on top of a 'git_odb'.

	Eventually, it will also manage other repository
	attributes (e.g. tag resolution, references, etc).

	See: src/git/repository.h

*	A new external method
		'git_repository_lookup(repo, oid, type)'
	has been added to the 'git_repository' API.

	All object lookups (git_XXX_lookup()) are now
	wrappers to this method, and duplicated code
	has been removed. The method does automatic type
	checking and returns a generic 'git_revpool_object'
	that can be cast to any specific object.

	See: src/git/repository.h

*	The external methods for object parsing of repository
	objects (git_XXX_parse()) have been removed.

	Loading objects from the repository is now managed
	through the 'lookup' functions. These objects are
	loaded with minimal information, and the relevant
	parsing is done automatically when the user requests
	any of the parsed attributes through accessor methods.

	An attribute has been added to 'git_repository' in
	order to force the parsing of all the repository objects
	immediately after lookup.

	See: src/git/commit.h
	See: src/git/tag.h
	See: src/git/tree.h

*	The previous walking functionality of the revpool
	is now found in 'git_revwalk', which does the actual
	revision walking on a repository; the attributes
	when walking through commits in a database have been
	decoupled from the actual commit objects.
	This increases performance when accessing commits
	during the walk and allows to have several
	'git_revwalk' instances working at the same time on
	top of the same repository, without having to load
	commits in memory several times.

	See: src/git/revwalk.h

*	The old 'git_revpool_table' has been renamed to
	'git_hashtable' and now works as a generic hashtable
	with support for any kind of object and custom hash
	functions.

	See: src/hashtable.h

*	All the relevant unit tests have been updated, renamed
	and grouped accordingly.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Tag objects are now properly loaded from the revision pool.
New test t0801 checks for loading a parsing a series of tags, including
the tag of a tag.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The 'parse_oid' and 'parse_person' methods which were used by the commit
parser are now global so they can be used when parsing other objects.

The 'git_commit_person' struct has been changed to a generic
'git_person'.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Packed objects inside packfiles are now properly unpacked when calling
the git_odb__read_packed() method; delta'ed objects are also properly
generated when needed.

A new unit test 0204-readpack tries to read a couple hundred packed
objects from a standard packed repository.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

The basic information (pointed trees and blobs) of each tree object in a
revision pool can now be parsed and queried.

Signed-off-by: Vicent Marti <tanoku@gmail.com>