first commit

.github/workflows/CI.yml

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+# This file is autogenerated by maturin v1.4.0
+# To update, run
+#
+#    maturin generate-ci github
+#
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+      - master
+    tags:
+      - '*'
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  linux:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        target: [x86_64, x86, aarch64, armv7, s390x, ppc64le]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+      - name: Build wheels
+        uses: PyO3/maturin-action@v1
+        with:
+          target: ${{ matrix.target }}
+          args: --release --out dist --find-interpreter
+          sccache: 'true'
+          manylinux: auto
+      - name: Upload wheels
+        uses: actions/upload-artifact@v3
+        with:
+          name: wheels
+          path: dist
+
+  windows:
+    runs-on: windows-latest
+    strategy:
+      matrix:
+        target: [x64, x86]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+          architecture: ${{ matrix.target }}
+      - name: Build wheels
+        uses: PyO3/maturin-action@v1
+        with:
+          target: ${{ matrix.target }}
+          args: --release --out dist --find-interpreter
+          sccache: 'true'
+      - name: Upload wheels
+        uses: actions/upload-artifact@v3
+        with:
+          name: wheels
+          path: dist
+
+  macos:
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        target: [x86_64, aarch64]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+      - name: Build wheels
+        uses: PyO3/maturin-action@v1
+        with:
+          target: ${{ matrix.target }}
+          args: --release --out dist --find-interpreter
+          sccache: 'true'
+      - name: Upload wheels
+        uses: actions/upload-artifact@v3
+        with:
+          name: wheels
+          path: dist
+
+  sdist:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Build sdist
+        uses: PyO3/maturin-action@v1
+        with:
+          command: sdist
+          args: --out dist
+      - name: Upload sdist
+        uses: actions/upload-artifact@v3
+        with:
+          name: wheels
+          path: dist
+
+  release:
+    name: Release
+    runs-on: ubuntu-latest
+    if: "startsWith(github.ref, 'refs/tags/')"
+    needs: [linux, windows, macos, sdist]
+    steps:
+      - uses: actions/download-artifact@v3
+        with:
+          name: wheels
+      - name: Publish to PyPI
+        uses: PyO3/maturin-action@v1
+        env:
+          MATURIN_PYPI_TOKEN: ${{ secrets.PYPI_API_TOKEN }}
+        with:
+          command: upload
+          args: --non-interactive --skip-existing *

.gitignore

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+/target
+
+# Byte-compiled / optimized / DLL files
+__pycache__/
+.pytest_cache/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+.venv/
+env/
+bin/
+build/
+develop-eggs/
+dist/
+eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+include/
+man/
+venv/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+pip-selfcheck.json
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.cache
+nosetests.xml
+coverage.xml
+
+# Translations
+*.mo
+
+# Mr Developer
+.mr.developer.cfg
+.project
+.pydevproject
+
+# Rope
+.ropeproject
+
+# Django stuff:
+*.log
+*.pot
+
+.DS_Store
+
+# Sphinx documentation
+docs/_build/
+
+# PyCharm
+.idea/
+
+# VSCode
+.vscode/
+
+# Pyenv
+.python-version

Cargo.toml

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+[package]
+name = "priority-expiry-cache"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lib]
+name = "priority_expiry_cache"
+crate-type = ["cdylib"]
+
+[dependencies]
+pyo3 = "0.19.0"
+lru = "0.12.1"

Readme.md

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+# Priority-expiry-cache [![codecov](https://codecov.io/gh/LucaPaterlini/python-wrapper-priority-expiry-cache/graph/badge.svg?token=GIJFVWT7NC)](https://codecov.io/gh/LucaPaterlini/priority-expiry-cache)
+
+## Wrapper of the rust [cargo](https://crates.io/crates/priority-expiry-cache) 
+
+## Intro
+
+This problem is one of the famous questions asked in companies interviews,
+the like of tesla, amazon, bp, etc.
+
+[Tesla Phone Screen Cache Problem](https://medium.com/double-pointer/tesla-google-facebook-phone-screen-cache-problem-4e24f5b886f8)
+
+
+I personally found this question a bit too much for an hour interview,
+to go from ideation to writing a full code implementation.
+This crate it's an attempt to make asking this question obsolete
+and spare good candidates from a rejection for a problem which 
+is more based on intuition than on algo and data structures skills.
+
+For all of those interested in just having a good priority, expiry cache in place 
+feel free to look at the [official crate](https://crates.io/crates/priority-expiry-cache) of this crate send prs 
+and tickets at the official github repo.
+
+All code is released under and informal
+[Beerware](https://en.wikipedia.org/wiki/Beerware) licence.
+
+## Problem Statement
+
+The problem statement requires us to design a cache with the following methods:
+
+- get(String key)
+- set(String key, String value, int priority, int expiry)
+- evictItem(int currentTime)
+
+The rules by which the cache operates is are follows:
+
+1. If an expired item is available. Remove it. If multiple items have the same expiry, removing any one suffices.
+2. If condition #1 can’t be satisfied, remove an item with the least priority.
+3. If more than one item satisfies condition #2, remove the least recently used one.
+4. Multiple items can have the same priority and expiry.
+
+Untold rules:
+ - All of those operations should be O(1) time and space complexity.
+
+## 1 Min Solution summary
+
+It's an extension of the [LRU Cache Wikipedia](https://en.wikipedia.org/wiki/Cache_replacement_policies#Least_recently_used_(LRU))
+as explained in this implementation [LRU Cache Interview Cake](https://www.interviewcake.com/concept/java/lru-cache)
+the difference it's the addition of a binary tree to keep track of the min and max priority and expiry.
+
+## Solution
+
+Assumptions:
+ - all the parameters do have fixed length e.g. String= len 1024; Int = u32
+
+Data structure used:
+ - [Doubly linked list](https://en.wikipedia.org/wiki/Doubly_linked_list)
+ - [Binary Tree](https://en.wikipedia.org/wiki/Binary_tree)
+ - [Hash map](https://en.wikipedia.org/wiki/Hash_table)
+
+### Set O(1) time and space
+Let's start from set, to reduce the Lookup time we are going to use hashmap to store a reference
+to the object that will encapsulate the "value" parameters at cost O(K) time and space
+assuming the map its pre-initialized, now K is the length of the String because it will be the input of our
+hash function, given our assumption is value it's a fixed length then O(1) will be our cost.
+
+Now we can make an assumption that the int it's a finite number say u32, this means we can construct
+a binary tree with a depth of 32 with access time of O(32) therefore O(1) time and space.
+
+This way we can build 2 binary trees that will give us the min and max priority and expiry in O(1) cost.
+to satisfy rule 4 we need as well to use a double linked list as leaf level of the binary trees
+so we can have multiple items with the same expiry or same priority and to satisfy rule 3 about
+the removal of the least recently used.
+
+The complexity is O(1) for the insertion + O(1) for the insertion binary tree of priority and expiry O(K)x2 
+assuming K its constant then O(1)+O(1)x2 = O(1) time and space. 
+
+### Get O(1) time and space
+
+The get is simpler because we only have to access the hashmap to get the reference to the object which
+we do already know happens in O(1) time and space.
+
+And
+
+Keep the expiry least used doubly linked list on both expiry and priority consistent
+we are going to move the item to the head of the list, this way we can keep track of the 
+least recently used O(1).
+
+The complexity is O(1) for the lookup + O(1) for the insertion binary tree of priority and expiry O(K)x2
+assuming K its constant then O(1)+O(1)x2 = O(1) time and space.
+
+
+### EvictItem O(1) time and space
+
+Following rule number 1 we are going to get the min expiry time in O(1) thanks to the binary tree mentioned earlier,
+and delete the first item, as policy we are using the least recently used for both expiry and priority.
+
+As requested if the min it's still not expired we are going to get in O(1) the min priority,
+and we can remove the least recently used thanks to the doubly linked list.
+
+The complexity is O(1)x2 for the find of the min expiry time and the min in priority and O(1)
+to remove the tail of the doubly linked list = O(1) time and space.
+
+
+## Credits
+- [Giacomo Sorbi](https://www.linkedin.com/in/giacomosorbi/) for proofreading
+- [Maturin](https://pypi.org/project/maturin/) for the wrapper scaffolding

pyproject.toml

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+[build-system]
+requires = ["maturin>=1.4,<2.0"]
+build-backend = "maturin"
+
+[project]
+name = "priority-expiry-cache"
+requires-python = ">=3.8"
+classifiers = [
+    "Programming Language :: Rust",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: Python :: Implementation :: PyPy",
+]
+[project.optional-dependencies]
+tests = [
+    "pytest",
+]
+dynamic = ["version"]
+
+[tool.maturin]
+python-source = "python"
+features = ["pyo3/extension-module"]

python/priority_expiry_cache/__init__.py

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+from .priority_expiry_cache import *
+
+
+__doc__ = priority_expiry_cache.__doc__
+if hasattr(priority_expiry_cache, "__all__"):
+    __all__ = priority_expiry_cache.__all__