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|
package post
import (
"database/sql"
"fmt"
"path"
"code.betamike.com/mediocregopher/mediocre-blog/src/cfg"
migrate "github.com/rubenv/sql-migrate"
_ "github.com/mattn/go-sqlite3" // we need dis
)
var migrations = &migrate.MemoryMigrationSource{Migrations: []*migrate.Migration{
{
Id: "1",
Up: []string{
`CREATE TABLE posts (
id TEXT NOT NULL PRIMARY KEY,
title TEXT NOT NULL,
description TEXT NOT NULL,
series TEXT,
published_at INTEGER NOT NULL,
last_updated_at INTEGER,
body TEXT NOT NULL
)`,
`CREATE TABLE post_tags (
post_id TEXT NOT NULL,
tag TEXT NOT NULL,
UNIQUE(post_id, tag)
)`,
`CREATE TABLE assets (
id TEXT NOT NULL PRIMARY KEY,
body BLOB NOT NULL
)`,
},
},
{
Id: "2",
Up: []string{
`CREATE TABLE post_drafts (
id TEXT NOT NULL PRIMARY KEY,
title TEXT NOT NULL,
description TEXT NOT NULL,
tags TEXT,
series TEXT,
body TEXT NOT NULL
)`,
},
},
{
Id: "3",
Up: []string{
`ALTER TABLE post_drafts RENAME description TO description_old`,
`ALTER TABLE post_drafts ADD COLUMN description TEXT`,
`UPDATE post_drafts AS pd SET description=pd.description_old`,
`ALTER TABLE post_drafts DROP COLUMN description_old`,
`ALTER TABLE posts RENAME description TO description_old`,
`ALTER TABLE posts ADD COLUMN description TEXT`,
`UPDATE posts AS p SET description=p.description_old`,
`ALTER TABLE posts DROP COLUMN description_old`,
},
},
{
Id: "4",
Up: []string{
`ALTER TABLE post_drafts ADD COLUMN format TEXT DEFAULT 'md'`,
`ALTER TABLE posts ADD COLUMN format TEXT DEFAULT 'md'`,
},
},
}}
// SQLDB is a sqlite3 database which can be used by storage interfaces within
// this package.
type SQLDB struct {
*sql.DB
}
// NewSQLDB initializes and returns a new sqlite3 database for storage
// intefaces. The db will be created within the given data directory.
func NewSQLDB(dataDir cfg.DataDir) (*SQLDB, error) {
path := path.Join(dataDir.Path, "post.sqlite3")
db, err := sql.Open("sqlite3", path)
if err != nil {
return nil, fmt.Errorf("opening sqlite file at %q: %w", path, err)
}
if _, err := migrate.Exec(db, "sqlite3", migrations, migrate.Up); err != nil {
return nil, fmt.Errorf("running migrations: %w", err)
}
return &SQLDB{db}, nil
}
// NewSQLDB is like NewSQLDB, but the database will be initialized in memory.
func NewInMemSQLDB() *SQLDB {
db, err := sql.Open("sqlite3", ":memory:")
if err != nil {
panic(fmt.Errorf("opening sqlite in memory: %w", err))
}
if _, err := migrate.Exec(db, "sqlite3", migrations, migrate.Up); err != nil {
panic(fmt.Errorf("running migrations: %w", err))
}
return &SQLDB{db}
}
// Close cleans up loose resources being held by the db.
func (db *SQLDB) Close() error {
return db.DB.Close()
}
// WithTx initializes a transaction, runs the callback using it, and either
// commits or rolls it back depending on if the callback returns an error.
func (db *SQLDB) WithTx(cb func(*sql.Tx) error) error {
tx, err := db.DB.Begin()
if err != nil {
return fmt.Errorf("starting transaction: %w", err)
}
if err := cb(tx); err != nil {
if rollbackErr := tx.Rollback(); rollbackErr != nil {
return fmt.Errorf(
"rolling back transaction: %w (original error: %v)",
rollbackErr, err,
)
}
return fmt.Errorf("performing transaction: %w (rolled back)", err)
}
if err := tx.Commit(); err != nil {
return fmt.Errorf("committing transaction: %w", err)
}
return nil
}
|
