Git tree objects.
parent
3cc9d74d05
commit
d27412d5c7
|
@ -181,7 +181,7 @@
|
||||||
"_journal/2024-02-17.md": "7c37cb10515ed3d2f5388eaf02a67048",
|
"_journal/2024-02-17.md": "7c37cb10515ed3d2f5388eaf02a67048",
|
||||||
"_journal/2024-02/2024-02-16.md": "e701902e369ec53098fc2deed4ec14fd",
|
"_journal/2024-02/2024-02-16.md": "e701902e369ec53098fc2deed4ec14fd",
|
||||||
"binary/integer-encoding.md": "7ace6ab6c5a4191ae0abdfe7e5abb6a2",
|
"binary/integer-encoding.md": "7ace6ab6c5a4191ae0abdfe7e5abb6a2",
|
||||||
"combinatorics/index.md": "200f23380b0817cc13a9acd40996b125",
|
"combinatorics/index.md": "477bfcad2d88edfb823072b8afb9d236",
|
||||||
"_journal/2024-02-18.md": "67e36dbbb2cac699d4533b5a2eaeb629",
|
"_journal/2024-02-18.md": "67e36dbbb2cac699d4533b5a2eaeb629",
|
||||||
"_journal/2024-02/2024-02-17.md": "7c37cb10515ed3d2f5388eaf02a67048",
|
"_journal/2024-02/2024-02-17.md": "7c37cb10515ed3d2f5388eaf02a67048",
|
||||||
"combinatorics/multiplicative-principle.md": "f1430302e0a35b863fa965a834c4e40a",
|
"combinatorics/multiplicative-principle.md": "f1430302e0a35b863fa965a834c4e40a",
|
||||||
|
@ -217,14 +217,15 @@
|
||||||
"_journal/2024-02/2024-02-27.md": "f75a0d04a875aeee932343dae0c78768",
|
"_journal/2024-02/2024-02-27.md": "f75a0d04a875aeee932343dae0c78768",
|
||||||
"filesystems/index.md": "cbd2b0290a3ba3b32abec4bd8bfefad5",
|
"filesystems/index.md": "cbd2b0290a3ba3b32abec4bd8bfefad5",
|
||||||
"filesystems/cas.md": "34906013a2a60fe5ee0e31809b4838aa",
|
"filesystems/cas.md": "34906013a2a60fe5ee0e31809b4838aa",
|
||||||
"git/objects.md": "b49015b8ebffc2c976d97b2484c74448",
|
"git/objects.md": "b95228a78744d3f9fe173e575aa0445a",
|
||||||
"git/index.md": "83d2d95fc549d9e8436946c7bd058d15",
|
"git/index.md": "83d2d95fc549d9e8436946c7bd058d15",
|
||||||
"encoding/integer.md": "5dd3a961bf259e53da207209051b8335",
|
"encoding/integer.md": "5dd3a961bf259e53da207209051b8335",
|
||||||
"_journal/2024-02-29.md": "f610f3caed659c1de3eed5f226cab508",
|
"_journal/2024-02-29.md": "f610f3caed659c1de3eed5f226cab508",
|
||||||
"_journal/2024-02/2024-02-28.md": "7489377c014a2ff3c535d581961b5b82",
|
"_journal/2024-02/2024-02-28.md": "7489377c014a2ff3c535d581961b5b82",
|
||||||
"_journal/2024-03-01.md": "e5602f6d41ae9dde85385428ad637d5a",
|
"_journal/2024-03-01.md": "a532486279190b0c12954966cbf8c3fe",
|
||||||
"_journal/2024-02/2024-02-29.md": "0e502a2c8baf90c2f12859b03f10b5a1",
|
"_journal/2024-02/2024-02-29.md": "0e502a2c8baf90c2f12859b03f10b5a1",
|
||||||
"algebra/sequences.md": "97c217823aacf8910a1a37bde694ecfe"
|
"algebra/sequences.md": "97c217823aacf8910a1a37bde694ecfe",
|
||||||
|
"algebra/sequences/index.md": "e5a7cdfbcb61709ce2963c4b5e53a8f2"
|
||||||
},
|
},
|
||||||
"fields_dict": {
|
"fields_dict": {
|
||||||
"Basic": [
|
"Basic": [
|
||||||
|
|
|
@ -13,3 +13,4 @@ title: "2024-03-01"
|
||||||
* Reviewed database reading/videos from yesterday with Kevin.
|
* Reviewed database reading/videos from yesterday with Kevin.
|
||||||
* Finished planning soft skills course with Gus.
|
* Finished planning soft skills course with Gus.
|
||||||
* Added flashcards around sequences.
|
* Added flashcards around sequences.
|
||||||
|
* Added flashcards for git trees.
|
|
@ -10,6 +10,8 @@ tags:
|
||||||
|
|
||||||
## Overview
|
## Overview
|
||||||
|
|
||||||
|
Git has a few fundamental types that serve as the foundation for its [[cas|CAS]] system, expanded upon in each subsequent section.
|
||||||
|
|
||||||
%%ANKI
|
%%ANKI
|
||||||
Basic
|
Basic
|
||||||
What cryptographic hash function does git use internally?
|
What cryptographic hash function does git use internally?
|
||||||
|
@ -106,22 +108,6 @@ Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Soft
|
||||||
<!--ID: 1709177255627-->
|
<!--ID: 1709177255627-->
|
||||||
END%%
|
END%%
|
||||||
|
|
||||||
%%ANKI
|
|
||||||
Basic
|
|
||||||
What plumbing subcommand is used to generate an oid?
|
|
||||||
Back: `hash-object`
|
|
||||||
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
|
||||||
<!--ID: 1709177255632-->
|
|
||||||
END%%
|
|
||||||
|
|
||||||
%%ANKI
|
|
||||||
Basic
|
|
||||||
The `hash-object` subcommand optionally stores the resulting object in what directory?
|
|
||||||
Back: `.git/objects`
|
|
||||||
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
|
||||||
<!--ID: 1709177255637-->
|
|
||||||
END%%
|
|
||||||
|
|
||||||
%%ANKI
|
%%ANKI
|
||||||
Cloze
|
Cloze
|
||||||
The {object database} refers to the {`.git/objects`} directory.
|
The {object database} refers to the {`.git/objects`} directory.
|
||||||
|
@ -129,10 +115,132 @@ Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Soft
|
||||||
<!--ID: 1709177255644-->
|
<!--ID: 1709177255644-->
|
||||||
END%%
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
Where does e.g. `d670460b4b4aece5915caf5c68d12f560a9fe3e4` live in the object database?
|
||||||
|
Back: At `.git/objects/d6/70460b4b4aece5915caf5c68d12f560a9fe3e4`.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709177255668-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What regular files exist in the object database after `git init`?
|
||||||
|
Back: None.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709177255672-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
Files in the object database are compressed using what format?
|
||||||
|
Back: The `zlib` data format.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254695-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What compression library does git use internally?
|
||||||
|
Back: `zlib`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254701-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
How do you decode e.g. `.git/objects/d6/70460b4b4aece5915caf5c68d12f560a9fe3e4`?
|
||||||
|
Back: By decompressing the `zlib` data formatted file.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254705-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What plumbing subcommand is used to inspect git objects?
|
||||||
|
Back: `cat-file`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254709-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What plumbing subcommand is typically used over manually decompressing with `zlib`?
|
||||||
|
Back: `cat-file`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254713-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What is the difference in output of manually decompressing `<OID>` and the following?
|
||||||
|
```bash
|
||||||
|
$ git cat-file -p <OID>
|
||||||
|
```
|
||||||
|
Back: Manual decompression includes the object header.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254716-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
## Blobs
|
||||||
|
|
||||||
|
The **b**inary **l**arge **ob**ject (blob) is used to represent arbitrary files.
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
Why are git blobs named the way they are?
|
||||||
|
Back: It is an acronym for **b**inary **l**arge **ob**ject.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254720-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
A regular file is stored as what kind of git object?
|
||||||
|
Back: A blob.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254723-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What does the decompressed header of a blob object look like?
|
||||||
|
Back: `blob <size><NUL>`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254726-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What is the value of `<size>` found in the header of a blob file?
|
||||||
|
Back: The number of bytes of the decompressed content.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254730-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What is the decompressed text of the blob generated by the following?
|
||||||
|
```bash
|
||||||
|
$ echo -n "abcd" | git hash-object -w --stdin
|
||||||
|
```
|
||||||
|
Back: `blob 4\0abcd`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254733-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
The `hash-object` subcommand optionally stores a created object in what directory?
|
||||||
|
Back: `.git/objects`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709177255637-->
|
||||||
|
END%%
|
||||||
|
|
||||||
%%ANKI
|
%%ANKI
|
||||||
Basic
|
Basic
|
||||||
What does the `hash-object` subcommand return?
|
What does the `hash-object` subcommand return?
|
||||||
Back: The computed object id.
|
Back: The oid of the new blob object.
|
||||||
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
<!--ID: 1709177255651-->
|
<!--ID: 1709177255651-->
|
||||||
END%%
|
END%%
|
||||||
|
@ -155,18 +263,165 @@ END%%
|
||||||
|
|
||||||
%%ANKI
|
%%ANKI
|
||||||
Basic
|
Basic
|
||||||
Where does object e.g. `d670460b4b4aece5915caf5c68d12f560a9fe3e4` live in the object database?
|
What is the result of the following command?
|
||||||
Back: At `.git/objects/d6/70460b4b4aece5915caf5c68d12f560a9fe3e4`.
|
```bash
|
||||||
|
$ echo -n "abcd" | git hash-object --stdin
|
||||||
|
```
|
||||||
|
Back: An oid (usually a SHA-1 hash).
|
||||||
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
<!--ID: 1709177255668-->
|
<!--ID: 1709345254736-->
|
||||||
END%%
|
END%%
|
||||||
|
|
||||||
%%ANKI
|
%%ANKI
|
||||||
Basic
|
Basic
|
||||||
What regular files exist in the object database after `git init`?
|
What plumbing subcommand is used to create blobs?
|
||||||
Back: None.
|
Back: `hash-object`
|
||||||
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
<!--ID: 1709177255672-->
|
<!--ID: 1709348481684-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
## Trees
|
||||||
|
|
||||||
|
The tree is used to represent directories. It maintains filenames of any contained blobs.
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What git object maintains filenames?
|
||||||
|
Back: Trees.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481689-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
A directory is stored as what kind of git object?
|
||||||
|
Back: Trees.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481693-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
All the *content* of a git repository is stored as what kind of git objects?
|
||||||
|
Back: Trees and blobs.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481696-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Cloze
|
||||||
|
A regular file is to {blob} objects as directories are to {tree} objects.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709345254740-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Cloze
|
||||||
|
{`hash-object`} is to blobs as {`write-tree`} is to trees.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481699-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What does the decompressed header of a tree object look like?
|
||||||
|
Back: `tree <size><NUL>`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481704-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What does the decompressed header of an empty tree object look like?
|
||||||
|
Back: `tree 0<NUL>`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481711-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What plumbing subcommand is used to create trees?
|
||||||
|
Back: `write-tree`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481715-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
The `write-tree` subcommand stores the new tree object in what directory?
|
||||||
|
Back: `.git/objects`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481718-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
The `write-tree` subcommand creates a tree object from what?
|
||||||
|
Back: The current index.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481721-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What does the `write-tree` subcommand return?
|
||||||
|
Back: The oid of the new tree object.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481725-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
Why doesn't `write-tree` take any arguments?
|
||||||
|
Back: It creates a new tree from the current index.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709348481730-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
What plumbing subcommand is used to put tree objects into the staging area?
|
||||||
|
Back: `read-tree`
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709349279634-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
How does the following command update the index?
|
||||||
|
```bash
|
||||||
|
$ git read-tree d8329fc1cc938780ffdd9f94e0d364e0ea74f579
|
||||||
|
```
|
||||||
|
Back: It adds the contents of tree `d8329fc1cc938780ffdd9f94e0d364e0ea74f579`.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709349279641-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
How does the following command update the index?
|
||||||
|
```bash
|
||||||
|
$ git read-tree --prefix=foo d8329fc1cc938780ffdd9f94e0d364e0ea74f579
|
||||||
|
```
|
||||||
|
Back: It adds tree `d8329fc1cc938780ffdd9f94e0d364e0ea74f579` as subtree `foo`.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709349279646-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
Where does the `read-tree` subcommand read the tree into?
|
||||||
|
Back: The current index.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709349279652-->
|
||||||
|
END%%
|
||||||
|
|
||||||
|
%%ANKI
|
||||||
|
Basic
|
||||||
|
The `read-tree` and `write-tree` interact indirectly through what?
|
||||||
|
Back: The staging area.
|
||||||
|
Reference: Scott Chacon, *Pro Git*, Second edition, The Expert’s Voice in Software Development (New York, NY: Apress, 2014).
|
||||||
|
<!--ID: 1709349279660-->
|
||||||
END%%
|
END%%
|
||||||
|
|
||||||
## References
|
## References
|
||||||
|
|
Loading…
Reference in New Issue