{"id":17336488,"url":"https://github.com/knio/everdb","last_synced_at":"2026-02-03T20:07:22.527Z","repository":{"id":7920100,"uuid":"9306002","full_name":"Knio/everdb","owner":"Knio","description":"Fast and efficient on-disk data structures and embedded databases","archived":false,"fork":false,"pushed_at":"2016-08-23T06:12:18.000Z","size":332,"stargazers_count":5,"open_issues_count":0,"forks_count":1,"subscribers_count":2,"default_branch":"master","last_synced_at":"2025-03-27T07:30:06.005Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":null,"has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/Knio.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null}},"created_at":"2013-04-08T20:23:37.000Z","updated_at":"2022-11-10T23:47:59.000Z","dependencies_parsed_at":"2022-09-04T06:10:50.718Z","dependency_job_id":null,"html_url":"https://github.com/Knio/everdb","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/Knio/everdb","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Knio%2Feverdb","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Knio%2Feverdb/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Knio%2Feverdb/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Knio%2Feverdb/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/Knio","download_url":"https://codeload.github.com/Knio/everdb/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Knio%2Feverdb/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":264990571,"owners_count":23694453,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-10-15T15:30:32.690Z","updated_at":"2026-02-03T20:07:17.508Z","avatar_url":"https://github.com/Knio.png","language":null,"funding_links":[],"categories":[],"sub_categories":[],"readme":"everdb\n======\n\n*everdb* is an embedded database system. It operates as a programming library\nwith APIs to read, write, and access various on-disk data structures contained in a single regular file.\n\n*everdb* is currently in experemental development and is not fit for use. Please check back later for a working product.\n\n*everdb* currently has two implmementations: \n - [everdb-python](https://github.com/Knio/everdb-python)\n - [everdb-native](https://github.com/Knio/everdb-native)\n\n### Python\n[![Build Status][buildlogo-python]](https://travis-ci.org/Knio/everdb-python)\n[![Coverage Status][coveragelogo-python]](https://coveralls.io/r/Knio/everdb-python)\n\n[buildlogo-python]: https://travis-ci.org/Knio/everdb-python.svg?branch=master\n[coveragelogo-python]: https://img.shields.io/coveralls/Knio/everdb-python.svg?branch=master\n\n### C\n\n[![Build Status][buildlogo-native]](https://travis-ci.org/Knio/everdb-native)\n[![Coverage Status][coveragelogo-native]](https://coveralls.io/r/Knio/everdb-native)\n\n[buildlogo-native]: https://travis-ci.org/Knio/everdb-native.svg?branch=master\n[coveragelogo-native]: https://img.shields.io/coveralls/Knio/everdb-native.svg?branch=master\n\n\n## What is it for?\n\n\n*everdb* is:\n* Embedded (your application opens the database file directly)\n* Single-user (only one process can open the file at a time)\n* ACID compliant (supports transactions and guarantees data reliability)\n* Efficient (datastructures are fast, all operations do not need to load large\n  structures into memory, optimized for 4K RAM/disk sizes, etc)\n\n*everdb* is not:\n* Client-server (you do not connect to a database server)\n* SQL (or NoSQL) (you operate on the database structures directly though a\n  programming API, not by writing queries in SQL or JS)\n\n\n## Supported Data Structures\n\n*everdb* currently has planned support for the following data structures:\n - *blobs*\n - *arrays*\n - *hashes*\n\nLikely future additions include:\n- btrees\n- log structured merge trees\n- judy arrays\n- etc..\n\n\n### blobs\n\nA *blob* is a an arbitrary sized array of bytes. *blobs* support time and memort efficient random read, overwrite, and append in `O(n)` of the requested data (and not the total blob size, so you can efficiently append a single byte to a huge blob).\n\n#### Limitations\n- an empty blob uses 1 page (4KiB) of data in the database file\n- a blob cannot exceed 2128609280 bytes (slightly under 2GiB)\n\nPython example:\n```python\n\u003e\u003e\u003e blob = db.blob()\n\u003cBlob object\u003e\n\u003e\u003e\u003e blob[i]\nb\"X\"\n\u003e\u003e\u003e blob[j] = \"Y\"\n\u003e\u003e\u003e blob[i:j]\nb\"Hello World\"\n\u003e\u003e\u003e blob[i:j] = \"01234 56789\"\n\u003e\u003e\u003e blob.read(offset, length)\nb\"Hello World\"\n\u003e\u003e\u003e blob.write(offset, x)\n\u003e\u003e\u003e blob.append(x)\n\u003e\u003e\u003e blob.resize(n) # make blob n bytes long\n```\n\n\n### arrays\n\nAn *array* is similar to a *blob*, but instead of bytes, the content can be a multi-byte type. In Python, this can be any format supported by the `struct` module, and in C this can be any struct. Arrays have the same API as blobs, except can only access single elements at a time\n\n#### Limitations\nIn addition to the limits of *blob*:\n- the size of a single element in the array cannot exceed 1 page (4KiB)\n- if the size of a single element does not evenly divide 4KiB, there will be 4KiB % sizeof(type) wasted space per page of array data\n\nPython Example:\n```python\n\u003e\u003e\u003e array = db.array('IIHf')\n\u003e\u003e\u003e array[i]\n(1, 2, 3, 4.0)\n\u003e\u003e\u003e array[j] = (5, 6, 7, 8.9)\n\u003e\u003e\u003e array.length\n1\n\u003e\u003e\u003e array.format\n'IIHd'\narray.item_size\n14\n```\n\n\n### hashes\n\n*hashes* are key-value stores where both the key and values are arbitrary-length byte arrays.\n\nTODO\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fknio%2Feverdb","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fknio%2Feverdb","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fknio%2Feverdb/lists"}