Document that in SHA-1 repositories, we use SHA-1 and in SHA-256
repositories, we use SHA-256, then replace all other uses of "SHA-1"
with something more neutral. Avoid referring to "160-bit" hash values.
Signed-off-by: Martin Ågren <martin.agren@xxxxxxxxx>
---
Documentation/technical/index-format.txt | 34 +++++++++++++-----------
1 file changed, 18 insertions(+), 16 deletions(-)
diff --git a/Documentation/technical/index-format.txt b/Documentation/technical/index-format.txt
index faa25c5c52..f9a3644711 100644
--- a/Documentation/technical/index-format.txt
+++ b/Documentation/technical/index-format.txt
@@ -3,8 +3,11 @@ Git index format
== The Git index file has the following format
- All binary numbers are in network byte order. Version 2 is described
- here unless stated otherwise.
+ All binary numbers are in network byte order.
+ In a repository using the traditional SHA-1, checksums and object IDs
+ (object names) mentioned below are all computed using SHA-1. Similarly,
+ in SHA-256 repositories, these values are computed using SHA-256.
+ Version 2 is described here unless stated otherwise.
- A 12-byte header consisting of
@@ -32,8 +35,7 @@ Git index format
Extension data
- - 160-bit SHA-1 over the content of the index file before this
- checksum.
+ - Hash checksum over the content of the index file before this checksum.
== Index entry
@@ -80,7 +82,7 @@ Git index format
32-bit file size
This is the on-disk size from stat(2), truncated to 32-bit.
- 160-bit SHA-1 for the represented object
+ Object name for the represented object
A 16-bit 'flags' field split into (high to low bits)
@@ -160,8 +162,8 @@ Git index format
- A newline (ASCII 10); and
- - 160-bit object name for the object that would result from writing
- this span of index as a tree.
+ - Object name for the object that would result from writing this span
+ of index as a tree.
An entry can be in an invalidated state and is represented by having
a negative number in the entry_count field. In this case, there is no
@@ -198,7 +200,7 @@ Git index format
stage 1 to 3 (a missing stage is represented by "0" in this field);
and
- - At most three 160-bit object names of the entry in stages from 1 to 3
+ - At most three object names of the entry in stages from 1 to 3
(nothing is written for a missing stage).
=== Split index
@@ -211,8 +213,8 @@ Git index format
The extension consists of:
- - 160-bit SHA-1 of the shared index file. The shared index file path
- is $GIT_DIR/sharedindex.<SHA-1>. If all 160 bits are zero, the
+ - Hash of the shared index file. The shared index file path
+ is $GIT_DIR/sharedindex.<hash>. If all bits are zero, the
index does not require a shared index file.
- An ewah-encoded delete bitmap, each bit represents an entry in the
@@ -253,10 +255,10 @@ Git index format
- 32-bit dir_flags (see struct dir_struct)
- - 160-bit SHA-1 of $GIT_DIR/info/exclude. Null SHA-1 means the file
+ - Hash of $GIT_DIR/info/exclude. A null hash means the file
does not exist.
- - 160-bit SHA-1 of core.excludesfile. Null SHA-1 means the file does
+ - Hash of core.excludesfile. A null hash means the file does
not exist.
- NUL-terminated string of per-dir exclude file name. This usually
@@ -285,13 +287,13 @@ The remaining data of each directory block is grouped by type:
- An ewah bitmap, the n-th bit records "check-only" bit of
read_directory_recursive() for the n-th directory.
- - An ewah bitmap, the n-th bit indicates whether SHA-1 and stat data
+ - An ewah bitmap, the n-th bit indicates whether hash and stat data
is valid for the n-th directory and exists in the next data.
- An array of stat data. The n-th data corresponds with the n-th
"one" bit in the previous ewah bitmap.
- - An array of SHA-1. The n-th SHA-1 corresponds with the n-th "one" bit
+ - An array of hashes. The n-th hash corresponds with the n-th "one" bit
in the previous ewah bitmap.
- One NUL.
@@ -330,12 +332,12 @@ The remaining data of each directory block is grouped by type:
- 32-bit offset to the end of the index entries
- - 160-bit SHA-1 over the extension types and their sizes (but not
+ - Hash over the extension types and their sizes (but not
their contents). E.g. if we have "TREE" extension that is N-bytes
long, "REUC" extension that is M-bytes long, followed by "EOIE",
then the hash would be:
- SHA-1("TREE" + <binary representation of N> +
+ Hash("TREE" + <binary representation of N> +
"REUC" + <binary representation of M>)
== Index Entry Offset Table
--
2.28.0.297.g1956fa8f8d
