From: Abhradeep Chakraborty <chakrabortyabhradeep79@xxxxxxxxx>
The asciidoc generated html for `Documentation/technical/bitmap-
format.txt` is broken. This is mainly because `-` is used for nested
lists (which is not allowed in asciidoc) instead of `*`.
Fix these and also reformat it (e.g. removing some blank lines) for
better readability of the html page.
Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@xxxxxxxxx>
---
Documentation/technical/bitmap-format.txt | 96 +++++++++++------------
1 file changed, 45 insertions(+), 51 deletions(-)
diff --git a/Documentation/technical/bitmap-format.txt b/Documentation/technical/bitmap-format.txt
index 04b3ec21785..110d7ddf8ed 100644
--- a/Documentation/technical/bitmap-format.txt
+++ b/Documentation/technical/bitmap-format.txt
@@ -39,7 +39,7 @@ MIDXs, both the bit-cache and rev-cache extensions are required.
== On-disk format
- - A header appears at the beginning:
+ * A header appears at the beginning:
4-byte signature: {'B', 'I', 'T', 'M'}
@@ -48,35 +48,30 @@ MIDXs, both the bit-cache and rev-cache extensions are required.
of the bitmap index (the same one as JGit).
2-byte flags (network byte order)
-
The following flags are supported:
-
- - BITMAP_OPT_FULL_DAG (0x1) REQUIRED
- This flag must always be present. It implies that the
- bitmap index has been generated for a packfile or
- multi-pack index (MIDX) with full closure (i.e. where
- every single object in the packfile/MIDX can find its
- parent links inside the same packfile/MIDX). This is a
- requirement for the bitmap index format, also present in
- JGit, that greatly reduces the complexity of the
- implementation.
-
- - BITMAP_OPT_HASH_CACHE (0x4)
- If present, the end of the bitmap file contains
- `N` 32-bit name-hash values, one per object in the
- pack/MIDX. The format and meaning of the name-hash is
- described below.
+ - BITMAP_OPT_FULL_DAG (0x1) REQUIRED
+ This flag must always be present. It implies that the
+ bitmap index has been generated for a packfile or
+ multi-pack index (MIDX) with full closure (i.e. where
+ every single object in the packfile/MIDX can find its
+ parent links inside the same packfile/MIDX). This is a
+ requirement for the bitmap index format, also present in
+ JGit, that greatly reduces the complexity of the
+ implementation.
+ - BITMAP_OPT_HASH_CACHE (0x4)
+ If present, the end of the bitmap file contains
+ `N` 32-bit name-hash values, one per object in the
+ pack/MIDX. The format and meaning of the name-hash is
+ described below.
4-byte entry count (network byte order)
-
The total count of entries (bitmapped commits) in this bitmap index.
20-byte checksum
-
The SHA1 checksum of the pack/MIDX this bitmap index
belongs to.
- - 4 EWAH bitmaps that act as type indexes
+ * 4 EWAH bitmaps that act as type indexes
Type indexes are serialized after the hash cache in the shape
of four EWAH bitmaps stored consecutively (see Appendix A for
@@ -84,7 +79,6 @@ MIDXs, both the bit-cache and rev-cache extensions are required.
There is a bitmap for each Git object type, stored in the following
order:
-
- Commits
- Trees
- Blobs
@@ -97,39 +91,39 @@ MIDXs, both the bit-cache and rev-cache extensions are required.
in a full set (all bits set), and the AND of all 4 bitmaps will
result in an empty bitmap (no bits set).
- - N entries with compressed bitmaps, one for each indexed commit
+ * N entries with compressed bitmaps, one for each indexed commit
Where `N` is the total amount of entries in this bitmap index.
Each entry contains the following:
- - 4-byte object position (network byte order)
- The position **in the index for the packfile or
- multi-pack index** where the bitmap for this commit is
- found.
-
- - 1-byte XOR-offset
- The xor offset used to compress this bitmap. For an entry
- in position `x`, a XOR offset of `y` means that the actual
- bitmap representing this commit is composed by XORing the
- bitmap for this entry with the bitmap in entry `x-y` (i.e.
- the bitmap `y` entries before this one).
-
- Note that this compression can be recursive. In order to
- XOR this entry with a previous one, the previous entry needs
- to be decompressed first, and so on.
-
- The hard-limit for this offset is 160 (an entry can only be
- xor'ed against one of the 160 entries preceding it). This
- number is always positive, and hence entries are always xor'ed
- with **previous** bitmaps, not bitmaps that will come afterwards
- in the index.
-
- - 1-byte flags for this bitmap
- At the moment the only available flag is `0x1`, which hints
- that this bitmap can be re-used when rebuilding bitmap indexes
- for the repository.
-
- - The compressed bitmap itself, see Appendix A.
+ ** 4-byte object position (network byte order)
+ The position **in the index for the packfile or
+ multi-pack index** where the bitmap for this commit is
+ found.
+
+ ** 1-byte XOR-offset
+ The xor offset used to compress this bitmap. For an entry
+ in position `x`, a XOR offset of `y` means that the actual
+ bitmap representing this commit is composed by XORing the
+ bitmap for this entry with the bitmap in entry `x-y` (i.e.
+ the bitmap `y` entries before this one).
+
+ Note that this compression can be recursive. In order to
+ XOR this entry with a previous one, the previous entry needs
+ to be decompressed first, and so on.
+
+ The hard-limit for this offset is 160 (an entry can only be
+ xor'ed against one of the 160 entries preceding it). This
+ number is always positive, and hence entries are always xor'ed
+ with **previous** bitmaps, not bitmaps that will come afterwards
+ in the index.
+
+ ** 1-byte flags for this bitmap
+ At the moment the only available flag is `0x1`, which hints
+ that this bitmap can be re-used when rebuilding bitmap indexes
+ for the repository.
+
+ ** The compressed bitmap itself, see Appendix A.
== Appendix A: Serialization format for an EWAH bitmap
--
gitgitgadget
