git/hex.c, branch v2.22.2

hex: introduce functions to print arbitrary hashes

2018-11-14T07:54:52Z

Currently, we have functions that turn an arbitrary SHA-1 value or an object ID into hex format, either using a static buffer or with a user-provided buffer. Add variants of these functions that can handle an arbitrary hash algorithm, specified by constant. Update the documentation as well. While we're at it, remove the "extern" declaration from this family of functions, since it's not needed and our style now recommends against it. We use the variant taking the algorithm structure pointer as the internal variant, since taking an algorithm pointer is the easiest way to handle all of the variants in use. Note that we maintain these functions because there are hashes which must change based on the hash algorithm in use but are not object IDs (such as pack checksums). Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

hex: switch to using the_hash_algo

2018-07-16T21:27:39Z

Instead of using the GIT_SHA1_* constants, switch to using the_hash_algo to convert object IDs to and from hex format. Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

notes: move hex_to_bytes() to hex.c and export it

2017-11-01T01:35:35Z

Make the function for converting pairs of hexadecimal digits to binary available to other call sites. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

Convert GIT_SHA1_HEXSZ used for allocation to GIT_MAX_HEXSZ

2017-03-27T05:08:21Z

Since we will likely be introducing a new hash function at some point, and that hash function might be longer than 40 hex characters, use the constant GIT_MAX_HEXSZ, which is designed to be suitable for allocations, instead of GIT_SHA1_HEXSZ. This will ease the transition down the line by distinguishing between places where we need to allocate memory suitable for the largest hash from those where we need to handle the current hash. Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

hex: introduce parse_oid_hex

2017-02-20T09:11:26Z

Introduce a function, parse_oid_hex, which parses a hexadecimal object ID and if successful, sets a pointer to just beyond the last character. This allows for simpler, more robust parsing without needing to hard-code integer values throughout the codebase. Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

hex: make wraparound of the index into ring-buffer explicit

2016-10-26T17:54:11Z

Overflow is defined for unsigned integers, but not for signed ones. We could make the ring-buffer index in sha1_to_hex() and get_pathname() unsigned to be on the safe side to resolve this, but let's make it explicit that we are wrapping around at whatever the number of elements the ring-buffer has. The compiler is smart enough to turn modulus into bitmask for these codepaths that use ring-buffers of a size that is a power of 2. Signed-off-by: René Scharfe Signed-off-by: Junio C Hamano

Merge branch 'rs/hex2chr' into maint

2016-09-19T20:51:43Z

Code cleanup. * rs/hex2chr: introduce hex2chr() for converting two hexadecimal digits to a character

introduce hex2chr() for converting two hexadecimal digits to a character

2016-09-07T17:42:46Z

Add and use a helper function that decodes the char value of two hexadecimal digits. It returns a negative number on error, avoids running over the end of the given string and doesn't shift negative values. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

hex: add oid_to_hex_r()

2016-06-28T18:39:02Z

This function works just like sha1_to_hex_r, except that it takes a pointer to struct object_id instead of a pointer to unsigned char. Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

add reentrant variants of sha1_to_hex and find_unique_abbrev

2015-09-25T17:18:18Z

The sha1_to_hex and find_unique_abbrev functions always write into reusable static buffers. There are a few problems with this: - future calls overwrite our result. This is especially annoying with find_unique_abbrev, which does not have a ring of buffers, so you cannot even printf() a result that has two abbreviated sha1s. - if you want to put the result into another buffer, we often strcpy, which looks suspicious when auditing for overflows. This patch introduces sha1_to_hex_r and find_unique_abbrev_r, which write into a user-provided buffer. Of course this is just punting on the overflow-auditing, as the buffer obviously needs to be GIT_SHA1_HEXSZ + 1 bytes. But it is much easier to audit, since that is a well-known size. We retain the non-reentrant forms, which just become thin wrappers around the reentrant ones. This patch also adds a strbuf variant of find_unique_abbrev, which will be handy in later patches. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano