Initial draft of libgit2

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

5 files changed, 408 insertions, 0 deletions

diff --git a/src/git_common.h b/src/git_common.h
new file mode 100644
index 000000000..f9fce2b42
--- /dev/null
+++ b/src/git_common.h
@@ -0,0 +1,83 @@
+/*
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef INCLUDE_git_common_h__
+#define INCLUDE_git_common_h__
+
+#ifdef __cplusplus
+# define GIT_BEGIN_DECL  extern "C" {
+# define GIT_END_DECL    }
+#else
+  /** Start declarations in C mode */
+# define GIT_BEGIN_DECL  /* empty */
+  /** End declarations in C mode */
+# define GIT_END_DECL    /* empty */
+#endif
+
+/**
+ * @file git_common.h
+ * @brief Git common platform definitions
+ * @defgroup git_common Git common platform definitions
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** Declare a public function exported for application use. */
+#define GIT_EXTERN(type) type
+
+/** Generic result code for any API call. */
+typedef int git_result;
+
+/** Operation completed successfully. */
+#define GIT_SUCCESS 0
+
+/**
+ * Operation failed, with unspecified reason.
+ * This value also serves as the base error code; all other
+ * error codes are subtracted from it such that all errors
+ * are < 0, in typical POSIX C tradition.
+ */
+#define GIT_ERROR -1
+
+/** Input was not a properly formatted Git object id. */
+#define GIT_ENOTOID (GIT_ERROR - 1)
+
+/** Input does not exist in the scope searched. */
+#define GIT_ENOTFOUND (GIT_ERROR - 2)
+
+/** @} */
+GIT_END_DECL
+#endif
diff --git a/src/git_odb.c b/src/git_odb.c
new file mode 100644
index 000000000..f1b16987e
--- /dev/null
+++ b/src/git_odb.c
@@ -0,0 +1,43 @@
+/*
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "git_odb.h"
+
+git_result git_odb_sread(git_sobj *out, git_odb *db, git_oid *id)
+{
+	if (!git_odb__sread_packed(out, db, id))
+		return GIT_SUCCESS;
+	return git_odb__sread_loose(out, db, id);
+}
diff --git a/src/git_odb.h b/src/git_odb.h
new file mode 100644
index 000000000..c72d81b5d
--- /dev/null
+++ b/src/git_odb.h
@@ -0,0 +1,133 @@
+/*
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef INCLUDE_git_odb_h__
+#define INCLUDE_git_odb_h__
+
+#include "git_common.h"
+#include "git_oid.h"
+#include <unistd.h>
+
+/**
+ * @file git_odb.h
+ * @brief Git object database routines
+ * @defgroup git_odb Git object database routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** An open object database handle. */
+typedef struct git_odb {
+	/** Path to the "objects" directory. */
+	const char *path;
+
+	/** Alternate databases to search. */
+	struct git_odb **alternates;
+
+	/** Number of alternates available. */
+	unsigned n_alternates;
+} git_odb;
+
+/**
+ * Open an object database for read/write access.
+ * @param out location to store the database pointer, if opened.
+ *            Set to NULL if the open failed.
+ * @param objects_dir path of the database's "objects" directory.
+ * @return GIT_SUCCESS if the database opened; otherwise an error
+ *         code describing why the open was not possible.
+ */
+GIT_EXTERN(git_result) git_odb_open(git_odb **out, const char *objects_dir);
+
+/**
+ * Close an open object database.
+ * @param db database pointer to close.  If NULL no action is taken.
+ *           The pointer is set to NULL when the close is completed.
+ */
+GIT_EXTERN(void) git_odb_close(git_odb** db);
+
+/** Basic type (loose or packed) of any Git object. */
+typedef enum {
+	OBJ_BAD = -1,       /**< Object is invalid. */
+	OBJ__EXT1 = 0,      /**< Reserved for future use. */
+	OBJ_COMMIT = 1,     /**< A commit object. */
+	OBJ_TREE = 2,       /**< A tree (directory listing) object. */
+	OBJ_BLOB = 3,       /**< A file revision object. */
+	OBJ_TAG = 4,        /**< An annotated tag object. */
+	OBJ__EXT2 = 5,      /**< Reserved for future use. */
+	OBJ_OFS_DELTA = 6,  /**< A delta, base is given by an offset. */
+	OBJ_REF_DELTA = 7,  /**< A delta, base is given by object id. */
+} git_otype;
+
+/** A small object read from the database. */
+typedef struct {
+	void *data;      /**< Raw, decompressed object data. */
+	size_t len;      /**< Total number of bytes in data. */
+	git_otype type;  /**< Type of this object. */
+} git_sobj;
+
+/**
+ * Read a small object from the database.
+ * @param out object descriptor to populate upon reading.
+ * @param db database to search for the object in.
+ * @param id identity of the object to read.
+ * @return GIT_SUCCESS if the object was read;
+ *         GIT_ENOTFOUND if the object is not in the database.
+ */
+GIT_EXTERN(git_result) git_odb_sread(git_sobj *out, git_odb *db, git_oid *id);
+
+/**
+ * Read a small object from the database using only pack files.
+ * @param out object descriptor to populate upon reading.
+ * @param db database to search for the object in.
+ * @param id identity of the object to read.
+ * @return GIT_SUCCESS if the object was read;
+ *         GIT_ENOTFOUND if the object is not in the database.
+ */
+GIT_EXTERN(git_result) git_odb__sread_packed(git_sobj *out, git_odb *db, git_oid *id);
+
+/**
+ * Read a small object from the database using only loose object files.
+ * @param out object descriptor to populate upon reading.
+ * @param db database to search for the object in.
+ * @param id identity of the object to read.
+ * @return GIT_SUCCESS if the object was read;
+ *         GIT_ENOTFOUND if the object is not in the database.
+ */
+GIT_EXTERN(git_result) git_odb__sread_loose(git_sobj *out, git_odb *db, git_oid *id);
+
+/** @} */
+GIT_END_DECL
+#endif
diff --git a/src/git_oid.c b/src/git_oid.c
new file mode 100644
index 000000000..d0a44bd6e
--- /dev/null
+++ b/src/git_oid.c
@@ -0,0 +1,73 @@
+/*
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "git_oid.h"
+#include <string.h>
+
+static signed char from_hex[] = {
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
+ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1, /* 30 */
+-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
+-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
+-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
+};
+
+git_result git_oid_mkstr(git_oid *out, const char *str)
+{
+	int p;
+	for (p = 0; p < sizeof(out->id); p++, str += 2) {
+		int v = (from_hex[str[0]] << 4) | from_hex[str[1]];
+		if (v < 0)
+			return GIT_ENOTOID;
+		out->id[p] = (unsigned char)v;
+	}
+	return GIT_SUCCESS;
+}
+
+void git_oid_mkraw(git_oid *out, const unsigned char *raw)
+{
+	memcpy(out->id, raw, sizeof(out->id));
+}
diff --git a/src/git_oid.h b/src/git_oid.h
new file mode 100644
index 000000000..5ec2b329a
--- /dev/null
+++ b/src/git_oid.h
@@ -0,0 +1,76 @@
+/*
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef INCLUDE_git_oid_h__
+#define INCLUDE_git_oid_h__
+
+#include "git_common.h"
+
+/**
+ * @file git_oid.h
+ * @brief Git object id routines
+ * @defgroup git_oid Git object id routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** Unique identity of any object (commit, tree, blob, tag). */
+typedef struct
+{
+	/** raw binary formatted id */
+	unsigned char id[20];
+} git_oid;
+
+/**
+ * Parse a hex formatted object id into a git_oid.
+ * @param out oid structure the result is written into.
+ * @param str input hex string; must be pointing at the start of
+ *        the hex sequence and have at least the number of bytes
+ *        needed for an oid encoded in hex (40 bytes).
+ * @return GIT_SUCCESS if valid; GIT_ENOTOID on failure.
+ */
+GIT_EXTERN(git_result) git_oid_mkstr(git_oid *out, const char *str);
+
+/**
+ * Copy an already raw oid into a git_oid structure.
+ * @param out oid structure the result is written into.
+ * @param raw the raw input bytes to be copied.
+ */
+GIT_EXTERN(void) git_oid_mkraw(git_oid *out, const unsigned char *raw);
+
+/** @} */
+GIT_END_DECL
+#endif