Merge pull request #1 from esl/rebased

Add initial code

.github/workflows/ci.yml

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+name: Erlang CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    container:
+      image: erlang:25
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Compile
+      run: rebar3 compile
+    - name: Run tests
+      run: rebar3 ct --sname=ct1
+
+  dialyzer:
+    runs-on: ubuntu-latest
+
+    container:
+      image: erlang:25
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Compile
+      run: rebar3 compile
+    - name: Run dialyzer
+      run: rebar3 dialyzer
+
+  xref:
+    runs-on: ubuntu-latest
+
+    container:
+      image: erlang:25
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Compile
+      run: rebar3 compile
+    - name: Run xref
+      run: rebar3 xref
+
+  erlfmt:
+    runs-on: ubuntu-latest
+
+    container:
+      image: erlang:25
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Run erlfmt
+      run: rebar3 fmt --check

.gitignore

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+_build/
+# vim temporary files
+*.sw*

README.md

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+# Cluster ETS
+
+The project adds replication support for Erlang Term Storage (ETS).
+
+It allows to insert or delete objects into ETS tables across several Erlang nodes.
+
+The closest comparison is Mnesia with dirty operations.
+
+Some features are not supported:
+- there is no schema
+- there is no persistency
+- there are no indexes
+- there are no transactions (there are bulk inserts/deletes instead).
+
+# Merging logic
+
+When two database partitions are joined together, records from both partitions
+are put together. So, each record would be present on each node.
+
+The idea that each node updates only records that it owns. The node name
+should be inside an ETS key for this to work (or a pid).
+
+When some node is down, we remove all records that are owned by this node.
+When a node reappears, the records are added back.
+
+# API
+
+The main module is cets.
+
+It exports functions:
+
+- `start(Tab, Opts)` - starts a new table manager.
+   There is one gen_server for each node for each table.
+- `insert(Server, Rec)` - inserts a new object into a table.
+- `insert_many(Server, Records)` - inserts several objects into a table.
+- `delete(Server, Key)` - deletes an object from the table.
+- `delete_many(Server, Keys)` - deletes several objects from the table.
+
+`cets_join` module contains the merging logic.
+
+`cets_discovery` module handles search of new nodes.
+
+It supports behaviours for different backends.
+
+It defines two callbacks:
+
+- `init/1` - inits the backend.
+- `get_nodes/1` - gets a list of alive erlang nodes.
+
+Once new nodes are found, `cets_discovery` calls `cets_join` module to merge two
+cluster partitions.
+
+The simplest `cets_discovery` backend is `cets_discovery_file`, which just reads
+a file with a list of nodes on each line. This file could be populated by an
+external program or by an admin.

rebar.config

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+{dialyzer, [
+    {warnings, [
+        no_return,
+        no_unused,
+        no_improper_lists,
+        no_fun_app,
+        no_match,
+        no_opaque,
+        no_fail_call,
+        no_contracts,
+        no_behaviours,
+        no_undefined_callbacks,
+        unmatched_returns,
+        error_handling,
+        underspecs
+        % overspecs, specdiffs
+    ]}
+]}.
+
+%% Enables "rebar3 fmt" command
+{project_plugins, [erlfmt]}.

rebar.lock

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+[].

run_test.sh

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+#!/usr/bin/env bash
+rebar3 ct --sname=ct1

src/cets.app.src

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+{application, cets, [
+    {description, "Clustered Erlang Term Storage"},
+    {vsn, "0.1"},
+    {modules, []},
+    {registered, []},
+    {applications, [kernel, stdlib]},
+    {env, []}
+    % {mod, {cets_app, []}
+]}.