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The storage engine (db-adapters)

priomptdb is the one copy of the storage engine. The server imports it, and any Go program can use it without a server.

import store "priomptdb"

st, _ := store.Open("prompts.db")                  // a file path -> SQLite
st, _ := store.Open("postgres://user:pw@host/db")  // a postgres:// DSN -> PostgreSQL

The API covers the whole lifecycle: Put/Get/List/Dump for the served HEAD, and Commit/Branch/Merge/Log/Resolve/SetBranch/GetCommit for history. Migrations run automatically and idempotently at Open, and PRIOMPT_ENCRYPTION_KEY turns on AES-256-GCM.

How backends plug in​

All SQL is portable and written once, with ? placeholders. A backend (a "dialect") only has to say three things:

type dialect struct {
    driver string                // database/sql driver name
    match  func(dsn string) bool // does this DSN belong to this backend?
    rebind func(q string) string // ?-style placeholders -> native style
}

Adding a database​

  1. Create <name>.go with a dialect var that blank-imports its driver. Copy the pattern in postgres.go.
  2. Add it to the dialects list in dialect.go, before sqlite. SQLite is the catch-all: any DSN no other dialect claims is treated as a file path.
  3. Check the upserts. The queries use ON CONFLICT, which SQLite and Postgres share. An engine without it (MySQL uses ON DUPLICATE KEY) needs a per-dialect upsert clause.

Tests run on SQLite in a temp directory. Run go test ./...; nothing needs installing.

Schema evolution​

Migrations are an ordered, append-only list. To change the schema, append a step. Never edit or reorder an existing one.