oid: give oids a type

`git_oid`s now have a type, and we require the oid type when creating
the object id from creation functions.

1 files changed, 36 insertions, 21 deletions

diff --git a/include/git2/oid.h b/include/git2/oid.h
index db433a0b4..8feb0a358 100644
--- a/include/git2/oid.h
+++ b/include/git2/oid.h
@@ -21,16 +21,16 @@ GIT_BEGIN_DECL
 
 /** The type of object id, currently only SHA1. */
 typedef enum {
-	GIT_OID_SHA1 = 1   /**< SHA1 */
+	GIT_OID_SHA1 = 1    /**< SHA1 */
 } git_oid_t;
 
 /** Size (in bytes) of a raw/binary oid */
-#define GIT_OID_SHA1_SIZE 20
-#define GIT_OID_MAX_SIZE  GIT_OID_SHA1_SIZE
+#define GIT_OID_SHA1_SIZE       20
+#define GIT_OID_MAX_SIZE        GIT_OID_SHA1_SIZE
 
 /** Size (in bytes) of a hex formatted oid */
-#define GIT_OID_SHA1_HEXSIZE (GIT_OID_SHA1_SIZE * 2)
-#define GIT_OID_MAX_HEXSIZE   GIT_OID_SHA1_HEXSIZE
+#define GIT_OID_SHA1_HEXSIZE   (GIT_OID_SHA1_SIZE * 2)
+#define GIT_OID_MAX_HEXSIZE     GIT_OID_SHA1_HEXSIZE
 
 /** Minimum length (in number of hex characters,
  * i.e. packets of 4 bits) of an oid prefix */
@@ -38,39 +38,49 @@ typedef enum {
 
 /** Unique identity of any object (commit, tree, blob, tag). */
 typedef struct git_oid {
+	/** type of object id */
+	unsigned char type;
+
 	/** raw binary formatted id */
-	unsigned char id[GIT_OID_SHA1_SIZE];
+	unsigned char id[GIT_OID_MAX_SIZE];
 } git_oid;
 
 /**
  * The binary representation of the null object ID.
  */
-#define GIT_OID_SHA1_ZERO { { 0 } }
+#define GIT_OID_SHA1_ZERO   { GIT_OID_SHA1,   { 0 } }
 
 /**
  * The string representation of the null object ID.
  */
-#define GIT_OID_SHA1_HEXZERO "0000000000000000000000000000000000000000"
+#define GIT_OID_SHA1_HEXZERO   "0000000000000000000000000000000000000000"
 
 /**
  * Parse a hex formatted object id into a git_oid.
  *
+ * The appropriate number of bytes for the given object ID type will
+ * be read from the string - 40 bytes for SHA1, 64 bytes for SHA256.
+ * The given string need not be NUL terminated.
+ *
  * @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).
+ *		needed for an oid encoded in hex (40 bytes for sha1,
+ *		256 bytes for sha256).
+ * @param type the type of object id
  * @return 0 or an error code
  */
-GIT_EXTERN(int) git_oid_fromstr(git_oid *out, const char *str);
+GIT_EXTERN(int) git_oid_fromstr(git_oid *out, const char *str, git_oid_t type);
 
 /**
- * Parse a hex formatted null-terminated string into a git_oid.
+ * Parse a hex formatted NUL-terminated string into a git_oid.
  *
  * @param out oid structure the result is written into.
  * @param str input hex string; must be null-terminated.
+ * @param type the type of object id
  * @return 0 or an error code
  */
-GIT_EXTERN(int) git_oid_fromstrp(git_oid *out, const char *str);
+GIT_EXTERN(int) git_oid_fromstrp(git_oid *out, const char *str, git_oid_t type);
 
 /**
  * Parse N characters of a hex formatted object id into a git_oid.
@@ -81,9 +91,10 @@ GIT_EXTERN(int) git_oid_fromstrp(git_oid *out, const char *str);
  * @param out oid structure the result is written into.
  * @param str input hex string of at least size `length`
  * @param length length of the input string
+ * @param type the type of object id
  * @return 0 or an error code
  */
-GIT_EXTERN(int) git_oid_fromstrn(git_oid *out, const char *str, size_t length);
+GIT_EXTERN(int) git_oid_fromstrn(git_oid *out, const char *str, size_t length, git_oid_t type);
 
 /**
  * Copy an already raw oid into a git_oid structure.
@@ -92,16 +103,17 @@ GIT_EXTERN(int) git_oid_fromstrn(git_oid *out, const char *str, size_t length);
  * @param raw the raw input bytes to be copied.
  * @return 0 on success or error code
  */
-GIT_EXTERN(int) git_oid_fromraw(git_oid *out, const unsigned char *raw);
+GIT_EXTERN(int) git_oid_fromraw(git_oid *out, const unsigned char *raw, git_oid_t type);
 
 /**
  * Format a git_oid into a hex string.
  *
  * @param out output 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). Only the
- *		oid digits are written; a '\\0' terminator must be added
- *		by the caller if it is required.
+ *		needed for an oid encoded in hex (40 bytes for SHA1,
+ *		64 bytes for SHA256). Only the oid digits are written;
+ *		a '\\0' terminator must be added by the caller if it is
+ *		required.
  * @param id oid structure to format.
  * @return 0 on success or error code
  */
@@ -127,9 +139,10 @@ GIT_EXTERN(int) git_oid_nfmt(char *out, size_t n, const git_oid *id);
  *
  * @param out output 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 (41 bytes). Only the
- *		oid digits are written; a '\\0' terminator must be added
- *		by the caller if it is required.
+ *		needed for an oid encoded in hex (41 bytes for SHA1,
+ *		65 bytes for SHA256). Only the oid digits are written;
+ *		a '\\0' terminator must be added by the caller if it
+ *		is required.
  * @param id oid structure to format.
  * @return 0 on success, non-zero callback return value, or error code
  */
@@ -151,7 +164,9 @@ GIT_EXTERN(char *) git_oid_tostr_s(const git_oid *oid);
 /**
  * Format a git_oid into a buffer as a hex format c-string.
  *
- * If the buffer is smaller than GIT_OID_SHA1_HEXSIZE+1, then the resulting
+ * If the buffer is smaller than the size of a hex-formatted oid string
+ * plus an additional byte (GIT_OID_SHA_HEXSIZE + 1 for SHA1 or
+ * GIT_OID_SHA256_HEXSIZE + 1 for SHA256), then the resulting
  * oid c-string will be truncated to n-1 characters (but will still be
  * NUL-byte terminated).
  *