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| -rw-r--r-- | examples/general.c | 914 |
1 files changed, 457 insertions, 457 deletions
diff --git a/examples/general.c b/examples/general.c index 32fdaf407..036cd9e7d 100644 --- a/examples/general.c +++ b/examples/general.c @@ -52,479 +52,479 @@ static void check_error(int error_code, const char *action) return; printf("Error %d %s - %s\n", error_code, action, - (error && error->message) ? error->message : "???"); + (error && error->message) ? error->message : "???"); exit(1); } int main (int argc, char** argv) { - // Initialize the library, this will set up any global state which libgit2 needs - // including threading and crypto - git_libgit2_init(); + // Initialize the library, this will set up any global state which libgit2 needs + // including threading and crypto + git_libgit2_init(); - // ### Opening the Repository + // ### Opening the Repository - // There are a couple of methods for opening a repository, this being the - // simplest. There are also [methods][me] for specifying the index file - // and work tree locations, here we assume they are in the normal places. + // There are a couple of methods for opening a repository, this being the + // simplest. There are also [methods][me] for specifying the index file + // and work tree locations, here we assume they are in the normal places. // // (Try running this program against tests/resources/testrepo.git.) - // - // [me]: http://libgit2.github.com/libgit2/#HEAD/group/repository - int error; - const char *repo_path = (argc > 1) ? argv[1] : "/opt/libgit2-test/.git"; - git_repository *repo; - - error = git_repository_open(&repo, repo_path); - check_error(error, "opening repository"); - - // ### SHA-1 Value Conversions - - // For our first example, we will convert a 40 character hex value to the - // 20 byte raw SHA1 value. - printf("*Hex to Raw*\n"); - char hex[] = "4a202b346bb0fb0db7eff3cffeb3c70babbd2045"; - - // The `git_oid` is the structure that keeps the SHA value. We will use - // this throughout the example for storing the value of the current SHA - // key we're working with. - git_oid oid; - git_oid_fromstr(&oid, hex); - - // Once we've converted the string into the oid value, we can get the raw - // value of the SHA by accessing `oid.id` - - // Next we will convert the 20 byte raw SHA1 value to a human readable 40 - // char hex value. - printf("\n*Raw to Hex*\n"); - char out[GIT_OID_HEXSZ+1]; - out[GIT_OID_HEXSZ] = '\0'; - - // If you have a oid, you can easily get the hex value of the SHA as well. - git_oid_fmt(out, &oid); - printf("SHA hex string: %s\n", out); - - // ### Working with the Object Database - - // **libgit2** provides [direct access][odb] to the object database. The - // object database is where the actual objects are stored in Git. For - // working with raw objects, we'll need to get this structure from the - // repository. - // - // [odb]: http://libgit2.github.com/libgit2/#HEAD/group/odb - git_odb *odb; - git_repository_odb(&odb, repo); - - // #### Raw Object Reading - - printf("\n*Raw Object Read*\n"); - git_odb_object *obj; - git_otype otype; - const unsigned char *data; - const char *str_type; - - // We can read raw objects directly from the object database if we have - // the oid (SHA) of the object. This allows us to access objects without - // knowing their type and inspect the raw bytes unparsed. - error = git_odb_read(&obj, odb, &oid); - check_error(error, "finding object in repository"); - - // A raw object only has three properties - the type (commit, blob, tree - // or tag), the size of the raw data and the raw, unparsed data itself. - // For a commit or tag, that raw data is human readable plain ASCII - // text. For a blob it is just file contents, so it could be text or - // binary data. For a tree it is a special binary format, so it's unlikely - // to be hugely helpful as a raw object. - data = (const unsigned char *)git_odb_object_data(obj); - otype = git_odb_object_type(obj); - - // We provide methods to convert from the object type which is an enum, to - // a string representation of that value (and vice-versa). - str_type = git_object_type2string(otype); - printf("object length and type: %d, %s\n", - (int)git_odb_object_size(obj), - str_type); - - // For proper memory management, close the object when you are done with - // it or it will leak memory. - git_odb_object_free(obj); - - // #### Raw Object Writing - - printf("\n*Raw Object Write*\n"); - - // You can also write raw object data to Git. This is pretty cool because - // it gives you direct access to the key/value properties of Git. Here - // we'll write a new blob object that just contains a simple string. - // Notice that we have to specify the object type as the `git_otype` enum. - git_odb_write(&oid, odb, "test data", sizeof("test data") - 1, GIT_OBJ_BLOB); - - // Now that we've written the object, we can check out what SHA1 was - // generated when the object was written to our database. - git_oid_fmt(out, &oid); - printf("Written Object: %s\n", out); - - // ### Object Parsing - - // libgit2 has methods to parse every object type in Git so you don't have - // to work directly with the raw data. This is much faster and simpler - // than trying to deal with the raw data yourself. - - // #### Commit Parsing - - // [Parsing commit objects][pco] is simple and gives you access to all the - // data in the commit - the author (name, email, datetime), committer - // (same), tree, message, encoding and parent(s). - // - // [pco]: http://libgit2.github.com/libgit2/#HEAD/group/commit - - printf("\n*Commit Parsing*\n"); - - git_commit *commit; - git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479"); - - error = git_commit_lookup(&commit, repo, &oid); - check_error(error, "looking up commit"); - - const git_signature *author, *cmtter; - const char *message; - time_t ctime; - unsigned int parents, p; - - // Each of the properties of the commit object are accessible via methods, - // including commonly needed variations, such as `git_commit_time` which - // returns the author time and `git_commit_message` which gives you the - // commit message (as a NUL-terminated string). - message = git_commit_message(commit); - author = git_commit_author(commit); - cmtter = git_commit_committer(commit); - ctime = git_commit_time(commit); - - // The author and committer methods return [git_signature] structures, - // which give you name, email and `when`, which is a `git_time` structure, - // giving you a timestamp and timezone offset. - printf("Author: %s (%s)\n", author->name, author->email); - - // Commits can have zero or more parents. The first (root) commit will - // have no parents, most commits will have one (i.e. the commit it was - // based on) and merge commits will have two or more. Commits can - // technically have any number, though it's rare to have more than two. - parents = git_commit_parentcount(commit); - for (p = 0;p < parents;p++) { - git_commit *parent; - git_commit_parent(&parent, commit, p); - git_oid_fmt(out, git_commit_id(parent)); - printf("Parent: %s\n", out); - git_commit_free(parent); - } - - // Don't forget to close the object to prevent memory leaks. You will have - // to do this for all the objects you open and parse. - git_commit_free(commit); - - // #### Writing Commits - - // libgit2 provides a couple of methods to create commit objects easily as - // well. There are four different create signatures, we'll just show one - // of them here. You can read about the other ones in the [commit API - // docs][cd]. - // - // [cd]: http://libgit2.github.com/libgit2/#HEAD/group/commit - - printf("\n*Commit Writing*\n"); - git_oid tree_id, parent_id, commit_id; - git_tree *tree; - git_commit *parent; - - // Creating signatures for an authoring identity and time is simple. You - // will need to do this to specify who created a commit and when. Default - // values for the name and email should be found in the `user.name` and - // `user.email` configuration options. See the `config` section of this - // example file to see how to access config values. - git_signature_new((git_signature **)&author, - "Scott Chacon", "schacon@gmail.com", 123456789, 60); - git_signature_new((git_signature **)&cmtter, - "Scott A Chacon", "scott@github.com", 987654321, 90); - - // Commit objects need a tree to point to and optionally one or more - // parents. Here we're creating oid objects to create the commit with, - // but you can also use - git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1"); - git_tree_lookup(&tree, repo, &tree_id); - git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644"); - git_commit_lookup(&parent, repo, &parent_id); - - // Here we actually create the commit object with a single call with all - // the values we need to create the commit. The SHA key is written to the - // `commit_id` variable here. - git_commit_create_v( - &commit_id, /* out id */ - repo, - NULL, /* do not update the HEAD */ - author, - cmtter, - NULL, /* use default message encoding */ - "example commit", - tree, - 1, parent); - - // Now we can take a look at the commit SHA we've generated. - git_oid_fmt(out, &commit_id); - printf("New Commit: %s\n", out); - - // #### Tag Parsing - - // You can parse and create tags with the [tag management API][tm], which - // functions very similarly to the commit lookup, parsing and creation - // methods, since the objects themselves are very similar. - // - // [tm]: http://libgit2.github.com/libgit2/#HEAD/group/tag - printf("\n*Tag Parsing*\n"); - git_tag *tag; - const char *tmessage, *tname; - git_otype ttype; - - // We create an oid for the tag object if we know the SHA and look it up - // the same way that we would a commit (or any other object). - git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1"); - - error = git_tag_lookup(&tag, repo, &oid); - check_error(error, "looking up tag"); - - // Now that we have the tag object, we can extract the information it - // generally contains: the target (usually a commit object), the type of - // the target object (usually 'commit'), the name ('v1.0'), the tagger (a - // git_signature - name, email, timestamp), and the tag message. - git_tag_target((git_object **)&commit, tag); - tname = git_tag_name(tag); // "test" - ttype = git_tag_target_type(tag); // GIT_OBJ_COMMIT (otype enum) - tmessage = git_tag_message(tag); // "tag message\n" - printf("Tag Message: %s\n", tmessage); - - git_commit_free(commit); - - // #### Tree Parsing - - // [Tree parsing][tp] is a bit different than the other objects, in that - // we have a subtype which is the tree entry. This is not an actual - // object type in Git, but a useful structure for parsing and traversing - // tree entries. - // - // [tp]: http://libgit2.github.com/libgit2/#HEAD/group/tree - printf("\n*Tree Parsing*\n"); - - const git_tree_entry *entry; - git_object *objt; - - // Create the oid and lookup the tree object just like the other objects. - git_oid_fromstr(&oid, "2a741c18ac5ff082a7caaec6e74db3075a1906b5"); - git_tree_lookup(&tree, repo, &oid); - - // Getting the count of entries in the tree so you can iterate over them - // if you want to. - size_t cnt = git_tree_entrycount(tree); // 3 - printf("tree entries: %d\n", (int)cnt); - - entry = git_tree_entry_byindex(tree, 0); - printf("Entry name: %s\n", git_tree_entry_name(entry)); // "hello.c" - - // You can also access tree entries by name if you know the name of the - // entry you're looking for. - entry = git_tree_entry_byname(tree, "README"); - git_tree_entry_name(entry); // "hello.c" - - // Once you have the entry object, you can access the content or subtree - // (or commit, in the case of submodules) that it points to. You can also - // get the mode if you want. - git_tree_entry_to_object(&objt, repo, entry); // blob - - // Remember to close the looked-up object once you are done using it - git_object_free(objt); - - // #### Blob Parsing - - // The last object type is the simplest and requires the least parsing - // help. Blobs are just file contents and can contain anything, there is - // no structure to it. The main advantage to using the [simple blob - // api][ba] is that when you're creating blobs you don't have to calculate - // the size of the content. There is also a helper for reading a file - // from disk and writing it to the db and getting the oid back so you - // don't have to do all those steps yourself. - // - // [ba]: http://libgit2.github.com/libgit2/#HEAD/group/blob - - printf("\n*Blob Parsing*\n"); - git_blob *blob; - - git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08"); - git_blob_lookup(&blob, repo, &oid); - - // You can access a buffer with the raw contents of the blob directly. - // Note that this buffer may not be contain ASCII data for certain blobs - // (e.g. binary files): do not consider the buffer a NULL-terminated - // string, and use the `git_blob_rawsize` attribute to find out its exact - // size in bytes - printf("Blob Size: %ld\n", (long)git_blob_rawsize(blob)); // 8 - git_blob_rawcontent(blob); // "content" - - // ### Revwalking - - // The libgit2 [revision walking api][rw] provides methods to traverse the - // directed graph created by the parent pointers of the commit objects. - // Since all commits point back to the commit that came directly before - // them, you can walk this parentage as a graph and find all the commits - // that were ancestors of (reachable from) a given starting point. This - // can allow you to create `git log` type functionality. - // - // [rw]: http://libgit2.github.com/libgit2/#HEAD/group/revwalk - - printf("\n*Revwalking*\n"); - git_revwalk *walk; - git_commit *wcommit; - - git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644"); - - // To use the revwalker, create a new walker, tell it how you want to sort - // the output and then push one or more starting points onto the walker. - // If you want to emulate the output of `git log` you would push the SHA - // of the commit that HEAD points to into the walker and then start - // traversing them. You can also 'hide' commits that you want to stop at - // or not see any of their ancestors. So if you want to emulate `git log - // branch1..branch2`, you would push the oid of `branch2` and hide the oid - // of `branch1`. - git_revwalk_new(&walk, repo); - git_revwalk_sorting(walk, GIT_SORT_TOPOLOGICAL | GIT_SORT_REVERSE); - git_revwalk_push(walk, &oid); - - const git_signature *cauth; - const char *cmsg; - - // Now that we have the starting point pushed onto the walker, we start - // asking for ancestors. It will return them in the sorting order we asked - // for as commit oids. We can then lookup and parse the committed pointed - // at by the returned OID; note that this operation is specially fast - // since the raw contents of the commit object will be cached in memory - while ((git_revwalk_next(&oid, walk)) == 0) { - error = git_commit_lookup(&wcommit, repo, &oid); - check_error(error, "looking up commit during revwalk"); - - cmsg = git_commit_message(wcommit); - cauth = git_commit_author(wcommit); - printf("%s (%s)\n", cmsg, cauth->email); - - git_commit_free(wcommit); - } - - // Like the other objects, be sure to free the revwalker when you're done - // to prevent memory leaks. Also, make sure that the repository being - // walked it not deallocated while the walk is in progress, or it will - // result in undefined behavior - git_revwalk_free(walk); - - // ### Index File Manipulation - - // The [index file API][gi] allows you to read, traverse, update and write - // the Git index file (sometimes thought of as the staging area). - // - // [gi]: http://libgit2.github.com/libgit2/#HEAD/group/index - - printf("\n*Index Walking*\n"); - - git_index *index; - unsigned int i, ecount; - - // You can either open the index from the standard location in an open - // repository, as we're doing here, or you can open and manipulate any - // index file with `git_index_open_bare()`. The index for the repository - // will be located and loaded from disk. - git_repository_index(&index, repo); - - // For each entry in the index, you can get a bunch of information - // including the SHA (oid), path and mode which map to the tree objects - // that are written out. It also has filesystem properties to help - // determine what to inspect for changes (ctime, mtime, dev, ino, uid, - // gid, file_size and flags) All these properties are exported publicly in - // the `git_index_entry` struct - ecount = git_index_entrycount(index); - for (i = 0; i < ecount; ++i) { - const git_index_entry *e = git_index_get_byindex(index, i); - - printf("path: %s\n", e->path); - printf("mtime: %d\n", (int)e->mtime.seconds); - printf("fs: %d\n", (int)e->file_size); - } - - git_index_free(index); - - // ### References - - // The [reference API][ref] allows you to list, resolve, create and update - // references such as branches, tags and remote references (everything in - // the .git/refs directory). - // - // [ref]: http://libgit2.github.com/libgit2/#HEAD/group/reference - - printf("\n*Reference Listing*\n"); - - // Here we will implement something like `git for-each-ref` simply listing - // out all available references and the object SHA they resolve to. - git_strarray ref_list; - git_reference_list(&ref_list, repo); - - const char *refname; - git_reference *ref; - - // Now that we have the list of reference names, we can lookup each ref - // one at a time and resolve them to the SHA, then print both values out. - for (i = 0; i < ref_list.count; ++i) { - refname = ref_list.strings[i]; - git_reference_lookup(&ref, repo, refname); - - switch (git_reference_type(ref)) { - case GIT_REF_OID: - git_oid_fmt(out, git_reference_target(ref)); - printf("%s [%s]\n", refname, out); - break; - - case GIT_REF_SYMBOLIC: - printf("%s => %s\n", refname, git_reference_symbolic_target(ref)); - break; - default: - fprintf(stderr, "Unexpected reference type\n"); - exit(1); - } - } - - git_strarray_free(&ref_list); - - // ### Config Files - - // The [config API][config] allows you to list and updatee config values - // in any of the accessible config file locations (system, global, local). - // - // [config]: http://libgit2.github.com/libgit2/#HEAD/group/config + // + // [me]: http://libgit2.github.com/libgit2/#HEAD/group/repository + int error; + const char *repo_path = (argc > 1) ? argv[1] : "/opt/libgit2-test/.git"; + git_repository *repo; + + error = git_repository_open(&repo, repo_path); + check_error(error, "opening repository"); + + // ### SHA-1 Value Conversions + + // For our first example, we will convert a 40 character hex value to the + // 20 byte raw SHA1 value. + printf("*Hex to Raw*\n"); + char hex[] = "4a202b346bb0fb0db7eff3cffeb3c70babbd2045"; + + // The `git_oid` is the structure that keeps the SHA value. We will use + // this throughout the example for storing the value of the current SHA + // key we're working with. + git_oid oid; + git_oid_fromstr(&oid, hex); + + // Once we've converted the string into the oid value, we can get the raw + // value of the SHA by accessing `oid.id` + + // Next we will convert the 20 byte raw SHA1 value to a human readable 40 + // char hex value. + printf("\n*Raw to Hex*\n"); + char out[GIT_OID_HEXSZ+1]; + out[GIT_OID_HEXSZ] = '\0'; + + // If you have a oid, you can easily get the hex value of the SHA as well. + git_oid_fmt(out, &oid); + printf("SHA hex string: %s\n", out); + + // ### Working with the Object Database + + // **libgit2** provides [direct access][odb] to the object database. The + // object database is where the actual objects are stored in Git. For + // working with raw objects, we'll need to get this structure from the + // repository. + // + // [odb]: http://libgit2.github.com/libgit2/#HEAD/group/odb + git_odb *odb; + git_repository_odb(&odb, repo); + + // #### Raw Object Reading + + printf("\n*Raw Object Read*\n"); + git_odb_object *obj; + git_otype otype; + const unsigned char *data; + const char *str_type; + + // We can read raw objects directly from the object database if we have + // the oid (SHA) of the object. This allows us to access objects without + // knowing their type and inspect the raw bytes unparsed. + error = git_odb_read(&obj, odb, &oid); + check_error(error, "finding object in repository"); + + // A raw object only has three properties - the type (commit, blob, tree + // or tag), the size of the raw data and the raw, unparsed data itself. + // For a commit or tag, that raw data is human readable plain ASCII + // text. For a blob it is just file contents, so it could be text or + // binary data. For a tree it is a special binary format, so it's unlikely + // to be hugely helpful as a raw object. + data = (const unsigned char *)git_odb_object_data(obj); + otype = git_odb_object_type(obj); + + // We provide methods to convert from the object type which is an enum, to + // a string representation of that value (and vice-versa). + str_type = git_object_type2string(otype); + printf("object length and type: %d, %s\n", + (int)git_odb_object_size(obj), + str_type); + + // For proper memory management, close the object when you are done with + // it or it will leak memory. + git_odb_object_free(obj); + + // #### Raw Object Writing + + printf("\n*Raw Object Write*\n"); + + // You can also write raw object data to Git. This is pretty cool because + // it gives you direct access to the key/value properties of Git. Here + // we'll write a new blob object that just contains a simple string. + // Notice that we have to specify the object type as the `git_otype` enum. + git_odb_write(&oid, odb, "test data", sizeof("test data") - 1, GIT_OBJ_BLOB); + + // Now that we've written the object, we can check out what SHA1 was + // generated when the object was written to our database. + git_oid_fmt(out, &oid); + printf("Written Object: %s\n", out); + + // ### Object Parsing + + // libgit2 has methods to parse every object type in Git so you don't have + // to work directly with the raw data. This is much faster and simpler + // than trying to deal with the raw data yourself. + + // #### Commit Parsing + + // [Parsing commit objects][pco] is simple and gives you access to all the + // data in the commit - the author (name, email, datetime), committer + // (same), tree, message, encoding and parent(s). + // + // [pco]: http://libgit2.github.com/libgit2/#HEAD/group/commit + + printf("\n*Commit Parsing*\n"); + + git_commit *commit; + git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479"); + + error = git_commit_lookup(&commit, repo, &oid); + check_error(error, "looking up commit"); + + const git_signature *author, *cmtter; + const char *message; + time_t ctime; + unsigned int parents, p; + + // Each of the properties of the commit object are accessible via methods, + // including commonly needed variations, such as `git_commit_time` which + // returns the author time and `git_commit_message` which gives you the + // commit message (as a NUL-terminated string). + message = git_commit_message(commit); + author = git_commit_author(commit); + cmtter = git_commit_committer(commit); + ctime = git_commit_time(commit); + + // The author and committer methods return [git_signature] structures, + // which give you name, email and `when`, which is a `git_time` structure, + // giving you a timestamp and timezone offset. + printf("Author: %s (%s)\n", author->name, author->email); + + // Commits can have zero or more parents. The first (root) commit will + // have no parents, most commits will have one (i.e. the commit it was + // based on) and merge commits will have two or more. Commits can + // technically have any number, though it's rare to have more than two. + parents = git_commit_parentcount(commit); + for (p = 0;p < parents;p++) { + git_commit *parent; + git_commit_parent(&parent, commit, p); + git_oid_fmt(out, git_commit_id(parent)); + printf("Parent: %s\n", out); + git_commit_free(parent); + } + + // Don't forget to close the object to prevent memory leaks. You will have + // to do this for all the objects you open and parse. + git_commit_free(commit); + + // #### Writing Commits + + // libgit2 provides a couple of methods to create commit objects easily as + // well. There are four different create signatures, we'll just show one + // of them here. You can read about the other ones in the [commit API + // docs][cd]. + // + // [cd]: http://libgit2.github.com/libgit2/#HEAD/group/commit + + printf("\n*Commit Writing*\n"); + git_oid tree_id, parent_id, commit_id; + git_tree *tree; + git_commit *parent; + + // Creating signatures for an authoring identity and time is simple. You + // will need to do this to specify who created a commit and when. Default + // values for the name and email should be found in the `user.name` and + // `user.email` configuration options. See the `config` section of this + // example file to see how to access config values. + git_signature_new((git_signature **)&author, + "Scott Chacon", "schacon@gmail.com", 123456789, 60); + git_signature_new((git_signature **)&cmtter, + "Scott A Chacon", "scott@github.com", 987654321, 90); + + // Commit objects need a tree to point to and optionally one or more + // parents. Here we're creating oid objects to create the commit with, + // but you can also use + git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1"); + git_tree_lookup(&tree, repo, &tree_id); + git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644"); + git_commit_lookup(&parent, repo, &parent_id); + + // Here we actually create the commit object with a single call with all + // the values we need to create the commit. The SHA key is written to the + // `commit_id` variable here. + git_commit_create_v( + &commit_id, /* out id */ + repo, + NULL, /* do not update the HEAD */ + author, + cmtter, + NULL, /* use default message encoding */ + "example commit", + tree, + 1, parent); + + // Now we can take a look at the commit SHA we've generated. + git_oid_fmt(out, &commit_id); + printf("New Commit: %s\n", out); + + // #### Tag Parsing + + // You can parse and create tags with the [tag management API][tm], which + // functions very similarly to the commit lookup, parsing and creation + // methods, since the objects themselves are very similar. + // + // [tm]: http://libgit2.github.com/libgit2/#HEAD/group/tag + printf("\n*Tag Parsing*\n"); + git_tag *tag; + const char *tmessage, *tname; + git_otype ttype; + + // We create an oid for the tag object if we know the SHA and look it up + // the same way that we would a commit (or any other object). + git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1"); + + error = git_tag_lookup(&tag, repo, &oid); + check_error(error, "looking up tag"); + + // Now that we have the tag object, we can extract the information it + // generally contains: the target (usually a commit object), the type of + // the target object (usually 'commit'), the name ('v1.0'), the tagger (a + // git_signature - name, email, timestamp), and the tag message. + git_tag_target((git_object **)&commit, tag); + tname = git_tag_name(tag); // "test" + ttype = git_tag_target_type(tag); // GIT_OBJ_COMMIT (otype enum) + tmessage = git_tag_message(tag); // "tag message\n" + printf("Tag Message: %s\n", tmessage); + + git_commit_free(commit); + + // #### Tree Parsing + + // [Tree parsing][tp] is a bit different than the other objects, in that + // we have a subtype which is the tree entry. This is not an actual + // object type in Git, but a useful structure for parsing and traversing + // tree entries. + // + // [tp]: http://libgit2.github.com/libgit2/#HEAD/group/tree + printf("\n*Tree Parsing*\n"); + + const git_tree_entry *entry; + git_object *objt; + + // Create the oid and lookup the tree object just like the other objects. + git_oid_fromstr(&oid, "2a741c18ac5ff082a7caaec6e74db3075a1906b5"); + git_tree_lookup(&tree, repo, &oid); + + // Getting the count of entries in the tree so you can iterate over them + // if you want to. + size_t cnt = git_tree_entrycount(tree); // 3 + printf("tree entries: %d\n", (int)cnt); + + entry = git_tree_entry_byindex(tree, 0); + printf("Entry name: %s\n", git_tree_entry_name(entry)); // "hello.c" + + // You can also access tree entries by name if you know the name of the + // entry you're looking for. + entry = git_tree_entry_byname(tree, "README"); + git_tree_entry_name(entry); // "hello.c" + + // Once you have the entry object, you can access the content or subtree + // (or commit, in the case of submodules) that it points to. You can also + // get the mode if you want. + git_tree_entry_to_object(&objt, repo, entry); // blob + + // Remember to close the looked-up object once you are done using it + git_object_free(objt); + + // #### Blob Parsing + + // The last object type is the simplest and requires the least parsing + // help. Blobs are just file contents and can contain anything, there is + // no structure to it. The main advantage to using the [simple blob + // api][ba] is that when you're creating blobs you don't have to calculate + // the size of the content. There is also a helper for reading a file + // from disk and writing it to the db and getting the oid back so you + // don't have to do all those steps yourself. + // + // [ba]: http://libgit2.github.com/libgit2/#HEAD/group/blob + + printf("\n*Blob Parsing*\n"); + git_blob *blob; + + git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08"); + git_blob_lookup(&blob, repo, &oid); + + // You can access a buffer with the raw contents of the blob directly. + // Note that this buffer may not be contain ASCII data for certain blobs + // (e.g. binary files): do not consider the buffer a NULL-terminated + // string, and use the `git_blob_rawsize` attribute to find out its exact + // size in bytes + printf("Blob Size: %ld\n", (long)git_blob_rawsize(blob)); // 8 + git_blob_rawcontent(blob); // "content" + + // ### Revwalking + + // The libgit2 [revision walking api][rw] provides methods to traverse the + // directed graph created by the parent pointers of the commit objects. + // Since all commits point back to the commit that came directly before + // them, you can walk this parentage as a graph and find all the commits + // that were ancestors of (reachable from) a given starting point. This + // can allow you to create `git log` type functionality. + // + // [rw]: http://libgit2.github.com/libgit2/#HEAD/group/revwalk + + printf("\n*Revwalking*\n"); + git_revwalk *walk; + git_commit *wcommit; + + git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644"); + + // To use the revwalker, create a new walker, tell it how you want to sort + // the output and then push one or more starting points onto the walker. + // If you want to emulate the output of `git log` you would push the SHA + // of the commit that HEAD points to into the walker and then start + // traversing them. You can also 'hide' commits that you want to stop at + // or not see any of their ancestors. So if you want to emulate `git log + // branch1..branch2`, you would push the oid of `branch2` and hide the oid + // of `branch1`. + git_revwalk_new(&walk, repo); + git_revwalk_sorting(walk, GIT_SORT_TOPOLOGICAL | GIT_SORT_REVERSE); + git_revwalk_push(walk, &oid); + + const git_signature *cauth; + const char *cmsg; + + // Now that we have the starting point pushed onto the walker, we start + // asking for ancestors. It will return them in the sorting order we asked + // for as commit oids. We can then lookup and parse the committed pointed + // at by the returned OID; note that this operation is specially fast + // since the raw contents of the commit object will be cached in memory + while ((git_revwalk_next(&oid, walk)) == 0) { + error = git_commit_lookup(&wcommit, repo, &oid); + check_error(error, "looking up commit during revwalk"); + + cmsg = git_commit_message(wcommit); + cauth = git_commit_author(wcommit); + printf("%s (%s)\n", cmsg, cauth->email); + + git_commit_free(wcommit); + } + + // Like the other objects, be sure to free the revwalker when you're done + // to prevent memory leaks. Also, make sure that the repository being + // walked it not deallocated while the walk is in progress, or it will + // result in undefined behavior + git_revwalk_free(walk); + + // ### Index File Manipulation + + // The [index file API][gi] allows you to read, traverse, update and write + // the Git index file (sometimes thought of as the staging area). + // + // [gi]: http://libgit2.github.com/libgit2/#HEAD/group/index + + printf("\n*Index Walking*\n"); + + git_index *index; + unsigned int i, ecount; + + // You can either open the index from the standard location in an open + // repository, as we're doing here, or you can open and manipulate any + // index file with `git_index_open_bare()`. The index for the repository + // will be located and loaded from disk. + git_repository_index(&index, repo); + + // For each entry in the index, you can get a bunch of information + // including the SHA (oid), path and mode which map to the tree objects + // that are written out. It also has filesystem properties to help + // determine what to inspect for changes (ctime, mtime, dev, ino, uid, + // gid, file_size and flags) All these properties are exported publicly in + // the `git_index_entry` struct + ecount = git_index_entrycount(index); + for (i = 0; i < ecount; ++i) { + const git_index_entry *e = git_index_get_byindex(index, i); + + printf("path: %s\n", e->path); + printf("mtime: %d\n", (int)e->mtime.seconds); + printf("fs: %d\n", (int)e->file_size); + } + + git_index_free(index); + + // ### References + + // The [reference API][ref] allows you to list, resolve, create and update + // references such as branches, tags and remote references (everything in + // the .git/refs directory). + // + // [ref]: http://libgit2.github.com/libgit2/#HEAD/group/reference + + printf("\n*Reference Listing*\n"); + + // Here we will implement something like `git for-each-ref` simply listing + // out all available references and the object SHA they resolve to. + git_strarray ref_list; + git_reference_list(&ref_list, repo); + + const char *refname; + git_reference *ref; + + // Now that we have the list of reference names, we can lookup each ref + // one at a time and resolve them to the SHA, then print both values out. + for (i = 0; i < ref_list.count; ++i) { + refname = ref_list.strings[i]; + git_reference_lookup(&ref, repo, refname); + + switch (git_reference_type(ref)) { + case GIT_REF_OID: + git_oid_fmt(out, git_reference_target(ref)); + printf("%s [%s]\n", refname, out); + break; + + case GIT_REF_SYMBOLIC: + printf("%s => %s\n", refname, git_reference_symbolic_target(ref)); + break; + default: + fprintf(stderr, "Unexpected reference type\n"); + exit(1); + } + } + + git_strarray_free(&ref_list); + + // ### Config Files + + // The [config API][config] allows you to list and updatee config values + // in any of the accessible config file locations (system, global, local). + // + // [config]: http://libgit2.github.com/libgit2/#HEAD/group/config - printf("\n*Config Listing*\n"); + printf("\n*Config Listing*\n"); - const char *email; - int32_t j; + const char *email; + int32_t j; - git_config *cfg; + git_config *cfg; - // Open a config object so we can read global values from it. - char config_path[256]; - sprintf(config_path, "%s/config", repo_path); - check_error(git_config_open_ondisk(&cfg, config_path), "opening config"); + // Open a config object so we can read global values from it. + char config_path[256]; + sprintf(config_path, "%s/config", repo_path); + check_error(git_config_open_ondisk(&cfg, config_path), "opening config"); - git_config_get_int32(&j, cfg, "help.autocorrect"); - printf("Autocorrect: %d\n", j); + git_config_get_int32(&j, cfg, "help.autocorrect"); + printf("Autocorrect: %d\n", j); - git_config_get_string(&email, cfg, "user.email"); - printf("Email: %s\n", email); + git_config_get_string(&email, cfg, "user.email"); + printf("Email: %s\n", email); - // Finally, when you're done with the repository, you can free it as well. - git_repository_free(repo); + // Finally, when you're done with the repository, you can free it as well. + git_repository_free(repo); - return 0; + return 0; } |