Feature 152 folder store

.github/workflows/uv-package-test.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
     steps:
       - uses: actions/checkout@v5
 

.pre-commit-config.yaml

@@ -30,3 +30,15 @@ repos:
         args: ["--fix", "--show-fixes"]
       # then, format
       - id: ruff-format
+
+  # - repo: https://github.com/pre-commit/mirrors-mypy
+  #   rev: "v1.19.1"
+  #   hooks:
+  #     - id: mypy
+  #       name: mypy
+  #       entry: uv run mypy
+  #       files: src
+  #       types: [python]
+  #       pass_filenames: true
+  #       args: []
+  #       language: system

.vscode/settings.json

@@ -1,12 +1,11 @@
 {
-    "python.terminal.activateEnvInCurrentTerminal": true,
-    "python.testing.pytestArgs": [
-        "tests"
-    ],
-    "python.testing.unittestEnabled": false,
-    "python.testing.pytestEnabled": true,
-    "editor.formatOnSave": true,
-    "[python]": {
-        "editor.defaultFormatter": "ms-python.black-formatter"
-    }
+  "python.terminal.activateEnvInCurrentTerminal": true,
+  "python.testing.pytestArgs": ["tests"],
+  "python.testing.unittestEnabled": false,
+  "python.testing.pytestEnabled": true,
+  "editor.formatOnSave": true,
+  "[python]": {
+    "editor.defaultFormatter": "ms-python.black-formatter",
+  },
+  "python-envs.pythonProjects": [],
 }

folder_operations.md

@@ -0,0 +1,164 @@
+# Folders in HashStore
+
+Describes storing directory trees in hashstore (hs).
+
+## Assumptions
+
+- The root of a folder hierarchy is identified by a PID
+- A folder hierarchy (including content) identified by a PID is immutable
+- A mutation to a folder hierarchy results in a new folder hierarchy identified by a new PID
+- Any subfolder may optionally be identified by a PID
+- Any file contained within a folder hierarchy may be identified by a PID
+- Permissions are associated with a PID and so apply to content of PID identified containers or files.
+- A folder hierarchy may reference all or part of another identified folder hierarchy
+- A folder is represented by a `container` in hashstore.
+
+## Virtual hashstore
+
+When a folder is added to `hs`, it is necessary to calculate file and folder hashes and compare these with any existing content in the target `hs`. The efficiency of updating an existing folder entry in `hs` can be significantly improved by computing the hashes locally and determining what may need to be sent to the target `hs`. This is especially important for large folder structures that may have isolated changes.
+
+A virtual `hs` (`vhs`) is a local folder structure that is similar to a `hs` except that the content bytes are not stored (except for containers), only hashes of the content. Time stamps of the hash entries are compared with content time stamps to identify candidates for hash recalculation. If hash values have changed, then the files are tagged for upload to the target hs.
+
+A `vhs` is composed of CID and PID ref files, and container files for folder hashes. Even though content ids are calculated, the content files are not stored.
+
+
+
+## Containers
+
+Hashstore is augmented by adding an additional type of content that represents a `container`, the contents of which represent a single folder. A `container` has two types of entries: `file` that represents a single file and `folder` which represents a single subfolder. Each entry in a `container` has properties: `type`, `cid`, and `name`, where:
+
+`type` - Indicates if the entry is a folder (`0`) or file (`1`).
+
+`cid` - The content ID for the respective file or container.
+
+`name` - The name component of the path to the entry. i.e. The last path segment for a subfolder or the file name (without path) for a file.
+
+The CID for a container is computed from the serialized content on the container which includes the CID values for any subfolders. Hence, computing the CID for folders in a hierarchy requires a depth-first approach where the CIDs for leaves of a branch are computed before the branch.
+
+A container is serialized space delimited rows in a text file. Each row represents an entry in the container, with values `type`, `cid`, and `name` in that order. Since folder or file names *may* contain whitespace, the `name` entry consumes the remainder of the row.
+
+Since the CID for a container is dependent on its content, the content order is sorted by the `type` and `cid` values so hashing is consistent. Hence rows referencing subfolder containers will always appear before rows referencing files.
+
+For example, given the folder hierarchy:
+
+```
+PID_1             <- dbc15
+├── A             <- ad5eb
+│   ├── a1.txt
+│   └── a2.txt
+└── B             <- cc08d
+    └── b1.csv
+```
+
+The following `container` entries are created (`cid` values are truncated):
+
+Container `ad5eb`:
+```
+1 10fbd a1.txt
+1 c880c a2.txt
+```
+
+Container `cc08d`:
+```
+1 00e99 b1.csv
+```
+
+Container `dbc15`:
+```
+0 ad5eb A
+0 cc08d B
+```
+
+The hashstore entry for `PID_1` might be:
+```
+$ cat refs/pids/53/b2/f2/58a2f3061a7bee4ba8b157aab217795c4692e2a2d8856e2fd97eb7fa3f
+dbc1516e49e7437ea441f279570d32b1e2f149c44ab0a77682629215f4a5970b
+
+$ cat refs/cids/db/c1/51/6e49e7437ea441f279570d32b1e2f149c44ab0a77682629215f4a5970b
+PID_1
+```
+
+Each container is resolveable by the combination of PID and path. So for example,
+the folder `B` within the context of `PID_1` can be resolved using the identifier `PID_1 B`. 
+Similarly, the file `A/a2.txt` can be resolved with the identifier `PID_1 A/a2.txt`. 
+Corresponding entries in hashstore `refs/pids` and `refs/cids` are created.
+
+## Operations
+
+### Get an object by path
+
+Given a PID and a path, retrieve the corresponding object (file or folder) from hashstore.
+
+Persistent identifiers for objects within a folder hierarchy are constructed by concatenating the PID with the path using a space as a delimiter. For example, to retrieve the object at path `data/file1.txt` within the folder hierarchy identified by PID `abc123`, the identifier would be `abc123 data/file1.txt`.
+
+```
+hashstore = HashStore(...)
+path_pid = "<PID>" + " " + "<path>"
+object_stream = hashstore.retrieve_object(path_pid)
+```
+
+### Store a new folder hierarchy
+
+To store a new folder hierarchy, recursively create `container` entries for each folder in the hierarchy, starting from the leaves and working up to the root. For each folder, create a `container` with entries for its subfolders and files, compute the CID for the container, and store it in hashstore. Finally, associate the root container's CID with the PID representing the entire folder hierarchy.
+
+This is achieved by the `hashstore.store_folder()` method.
+
+```
+hashstore = HashStore(...)
+pid = "<PID>"
+source_path = "<local_folder_path>"
+hashstore.store_folder(pid, source_path)
+```
+
+### Retrieve folder hierarchy structure
+
+To retrieve the structure of a folder hierarchy identified by a PID, recursively resolve each `container` starting from the root PID. For each folder, read its `container` entries to identify subfolders and files, and continue resolving subfolders until the entire hierarchy is reconstructed.
+
+This is achieved by the `hashstore.retrieve_folder()` method.
+
+```
+hashstore = HashStore(...)
+pid = "<PID>"
+destination_path = "<local_folder_path>"
+hashstore.retrieve_folder(pid, destination_path)
+```
+
+
+---
+
+## `add`
+
+`add(PID:str, path:pathlib.Path)->None`
+
+Add an object or folder to `vhs`. 
+
+
+## `init`
+
+`init(path:pathlib.Path)->None`
+
+Initializes a `vhs` folder within the current folder.
+
+
+## `status`
+
+`status()->VhsStatus`
+
+Reports the status of the entries in the `vhs` versus the current contents of 
+registered content.
+
+
+## `update`
+
+`update(PID:str|None)`
+
+Recalculates CID values based on the current content of registered entries.
+
+
+## `commit`
+
+`commit()`
+
+Makes entries in the `vhs` immutable preventing any further updates to existing 
+PIDs. Any further changes require new PID.
+