diff options
Diffstat (limited to 'Documentation/technical')
| -rw-r--r-- | Documentation/technical/api-trace2.txt | 3 | ||||
| -rw-r--r-- | Documentation/technical/commit-graph-format.txt | 30 | ||||
| -rw-r--r-- | Documentation/technical/http-protocol.txt | 2 | ||||
| -rw-r--r-- | Documentation/technical/pack-protocol.txt | 6 |
4 files changed, 36 insertions, 5 deletions
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt index 4f07ceadcb..6b6085585d 100644 --- a/Documentation/technical/api-trace2.txt +++ b/Documentation/technical/api-trace2.txt @@ -656,7 +656,8 @@ The "exec_id" field is a command-unique id and is only useful if the ------------ `"def_param"`:: - This event is generated to log a global parameter. + This event is generated to log a global parameter, such as a config + setting, command-line flag, or environment variable. + ------------ { diff --git a/Documentation/technical/commit-graph-format.txt b/Documentation/technical/commit-graph-format.txt index a4f17441ae..1beef17182 100644 --- a/Documentation/technical/commit-graph-format.txt +++ b/Documentation/technical/commit-graph-format.txt @@ -17,6 +17,9 @@ metadata, including: - The parents of the commit, stored using positional references within the graph file. +- The Bloom filter of the commit carrying the paths that were changed between + the commit and its first parent, if requested. + These positional references are stored as unsigned 32-bit integers corresponding to the array position within the list of commit OIDs. Due to some special constants we use to track parents, we can store at most @@ -93,6 +96,33 @@ CHUNK DATA: positions for the parents until reaching a value with the most-significant bit on. The other bits correspond to the position of the last parent. + Bloom Filter Index (ID: {'B', 'I', 'D', 'X'}) (N * 4 bytes) [Optional] + * The ith entry, BIDX[i], stores the number of bytes in all Bloom filters + from commit 0 to commit i (inclusive) in lexicographic order. The Bloom + filter for the i-th commit spans from BIDX[i-1] to BIDX[i] (plus header + length), where BIDX[-1] is 0. + * The BIDX chunk is ignored if the BDAT chunk is not present. + + Bloom Filter Data (ID: {'B', 'D', 'A', 'T'}) [Optional] + * It starts with header consisting of three unsigned 32-bit integers: + - Version of the hash algorithm being used. We currently only support + value 1 which corresponds to the 32-bit version of the murmur3 hash + implemented exactly as described in + https://en.wikipedia.org/wiki/MurmurHash#Algorithm and the double + hashing technique using seed values 0x293ae76f and 0x7e646e2 as + described in https://doi.org/10.1007/978-3-540-30494-4_26 "Bloom Filters + in Probabilistic Verification" + - The number of times a path is hashed and hence the number of bit positions + that cumulatively determine whether a file is present in the commit. + - The minimum number of bits 'b' per entry in the Bloom filter. If the filter + contains 'n' entries, then the filter size is the minimum number of 64-bit + words that contain n*b bits. + * The rest of the chunk is the concatenation of all the computed Bloom + filters for the commits in lexicographic order. + * Note: Commits with no changes or more than 512 changes have Bloom filters + of length zero. + * The BDAT chunk is present if and only if BIDX is present. + Base Graphs List (ID: {'B', 'A', 'S', 'E'}) [Optional] This list of H-byte hashes describe a set of B commit-graph files that form a commit-graph chain. The graph position for the ith commit in this diff --git a/Documentation/technical/http-protocol.txt b/Documentation/technical/http-protocol.txt index 9c5b6f0fac..51a79e63de 100644 --- a/Documentation/technical/http-protocol.txt +++ b/Documentation/technical/http-protocol.txt @@ -216,7 +216,7 @@ smart server reply: S: 001e# service=git-upload-pack\n S: 0000 S: 004895dcfa3633004da0049d3d0fa03f80589cbcaf31 refs/heads/maint\0multi_ack\n - S: 0042d049f6c27a2244e12041955e262a404c7faba355 refs/heads/master\n + S: 003fd049f6c27a2244e12041955e262a404c7faba355 refs/heads/master\n S: 003c2cb58b79488a98d2721cea644875a8dd0026b115 refs/tags/v1.0\n S: 003fa3c2e2402b99163d1d59756e5f207ae21cccba4c refs/tags/v1.0^{}\n S: 0000 diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt index d5ce4eea8a..a4573d12ce 100644 --- a/Documentation/technical/pack-protocol.txt +++ b/Documentation/technical/pack-protocol.txt @@ -96,7 +96,7 @@ Basically what the Git client is doing to connect to an 'upload-pack' process on the server side over the Git protocol is this: $ echo -e -n \ - "0039git-upload-pack /schacon/gitbook.git\0host=example.com\0" | + "003agit-upload-pack /schacon/gitbook.git\0host=example.com\0" | nc -v example.com 9418 @@ -171,9 +171,9 @@ with a version number (if "version=1" is sent as an Extra Parameter), and a listing of each reference it has (all branches and tags) along with the object name that each reference currently points to. - $ echo -e -n "0044git-upload-pack /schacon/gitbook.git\0host=example.com\0\0version=1\0" | + $ echo -e -n "0045git-upload-pack /schacon/gitbook.git\0host=example.com\0\0version=1\0" | nc -v example.com 9418 - 000aversion 1 + 000eversion 1 00887217a7c7e582c46cec22a130adf4b9d7d950fba0 HEAD\0multi_ack thin-pack side-band side-band-64k ofs-delta shallow no-progress include-tag 00441d3fcd5ced445d1abc402225c0b8a1299641f497 refs/heads/integration |