dargres 4.0.2

Dargres is a pure-Dart PostgreSQL driver based on Python pg8000

Changelog

4.0.2

Fixed

• TLS (sslContext, requireSsl) failed on every connection with HandshakeException: Connection terminated during handshake: the subscription that read the answer to the SSLRequest was cancelled before the socket was handed to SecureSocket.secure, which ended the socket. It is paused instead, as postgres 3.x does.

4.0.1

Details: doc/release_notes_4.0.1.md.

Fixed

• money (and money[]) is the exact decimal amount ('1234.56', '-0.05'), as postgres_fork returns it. It was the lc_monetary text ('R$ 1.234,56'), with the currency symbol and the locale's separators.

• float4 read in text (cold executions, simple protocol) gave the shortest decimal (0.1), and in binary (warm executions) the float4 value (0.10000000149011612), so the same query returned two different doubles. Text is now read as a float4 and widened, as the binary format; float4[] too.

• DateTime parameters carry their zone: a local DateTime was sent without its offset, so the server read it in the session time zone (a process in UTC with a session in America/Sao_Paulo stored timestamptz three hours off).

• Transaction commands (COMMIT, ROLLBACK, SAVEPOINT) could wait forever after the transaction awaited other I/O, e.g. a second pool lease.

• PostgreSqlPool opens connections on demand instead of all slots at once.

• Text date/timestamp/timestamptz decoding no longer depends on the OS time zone (DST-gap shift, BC dates and LMT offsets now match binary).

• ? placeholders after a literal ending in \ are rewritten correctly.

• Typo in the missing MD5 password error message.

• A query issued on a CoreConnection (not on the TransactionContext) while another caller's runInTransaction callback ran failed on the extended protocol (queryNamed, queryUnnamed, queryMaps, ...: "A transaction is active"); it now waits for the commit or rollback, as the simple protocol did. Issued from the callback itself, it runs in the transaction (it threw, or for execute waited forever). See queueConcurrentCalls.

• A queued transaction no longer runs ahead of queries that arrived before it, and a query that waited for another caller's preparation of the same statement keeps its place: queries and transactions run in arrival order.

• runInTransaction/beginTransaction from inside a runInTransaction callback fails with a StateError (it waited for itself forever).

• COPY ... FROM STDIN hung the connection, and every caller queued behind it, forever; it now fails with SQLSTATE 57014 (there is no COPY IN API).

• An unnamed prepared statement (prepareStatement(isUnamedStatement: true)) executed whatever statement was parsed unnamed last, e.g. any caller's queryUnnamed: silently wrong results. It is parsed again on execution.

• CoreConnection.executeStatement(isDeallocate: true) reported a failed execution as an uncaught asynchronous error.

• Text float8 and numeric were not correctly rounded (0.1 + 0.2 read as 0.3000000000000001, the float8 maximum as Infinity, subnormals as 0): a cold (text) and a warm (binary) execution of one statement returned different doubles.

• Array parameters: a 'null' string element was sent as SQL NULL, and a NaN or infinite double element failed with 22P02.

• Multidimensional arrays, arrays with explicit bounds ([0:1]={1,2}) and json[]/jsonb[] with non-object elements failed to decode.

• DateTime parameters with a year before 1 (BC) or after 9999 were rejected by the server.

• DEALLOCATE PREPARE ALL, and DEALLOCATE ALL/DISCARD ALL after other statements of a simple query, left the statement cache stale: the next cached query failed with 26000.

• A query issued on the connection from a runInTransaction callback after the connection died under that transaction ran outside it, autocommitted on the reconnected session; it now fails with a StateError.

• With textCharset: 'ascii', a non-ASCII NOTICE (any localized one), notification payload or ParameterStatus closed the connection.

Added

• searchPath and sessionStatements, applied to every physical session (pool slots and reconnects included) before connect() completes.
• client_encoding (from textCharset) and DateStyle=ISO in the startup packet.
• Opt-in numericAsString for exact numeric values.
• queueConcurrentCalls (default true) on ConnectionSettings and CoreConnection; false makes queries from outside a running transaction fail instead of waiting.
• repository and issue_tracker in the pubspec.

4.0.0

Details: doc/release_notes_4.0.0.md and PERFORMANCE_MIGRATION.md.

High-performance rewrite: 2.0x–2.75x faster than postgres_fork in the recorded 10,000-row benchmarks (JIT and AOT).

Added

• Direct query APIs queryMaps, queryTyped<T>, queryEach and queryCached, with RowView and per-column ResultSchema decoders.
• Per-connection LRU prepared-statement cache (statementCacheCapacity).
• Selective binary result decoding, plus opt-in requireBinaryResults.
• Opt-in IANA time zone decoding.
• ReconnectPolicy, ping()/checkHealth(), command timeout with CancelRequest, and cancelCurrentQuery().
• Bounded pool admission queue (maxPendingOperations, PoolQueueFullException) and pool metrics.
• Zero runtime dependencies (internal crypto, encodings and pool).

Changed

• Cold queries send Parse + Describe + Bind + Execute + Sync in one batch; cache hits send only Bind + Execute + Sync.
• PostgreSqlPool leases one physical connection per operation/transaction and replaces sockets closed by timeouts.
• Hardened connect/reconnect/close, SCRAM and socket flushing.
• Minimum Dart SDK ^3.6.0.

Breaking changes

• Row[] returns Object?.
• The direct APIs take named parameters; ? placeholders are never auto-detected.
• RowView is valid only inside its synchronous callback; queryEach does not await asynchronous callbacks.
• PostgreSqlPool no longer implements ConnectionInterface.
• CoreConnection.close() is terminal.
• Removed QueryState/Query.state, PostgreSqlPool.restartOnTimeout and transaction timeoutInner.

3.1.2

• Fixed the default Location initialization to use UTC.

3.1.1

• Added flags to TimeZoneSettings for more flexible decoding of date, timestamp, and timestamptz values.

3.1.0

• Breaking change: decoded timestamp without time zone as a local DateTime and decoded timestamp with time zone using the timezone defined on the connection.

3.0.2

• Fixed setting application_name on PostgreSQL versions earlier than 8.2.

3.0.1

• Fixed a critical stack-overflow bug introduced in 3.0.0. Timeout parameters were removed from query execution methods such as queryNamed, queryUnnamed, querySimple, execute, prepareStatement, and executeStatement.

3.0.0

• Implemented PostgreSqlPool with optional automatic reconnect after a connection drop.

final settings = ConnectionSettings(
  user: 'user',
  database: 'database',
  host: 'localhost',
  port: 5433,
  password: 'password',
  textCharset: 'latin1',
  applicationName: 'dargres',
);
final conn = PostgreSqlPool(
  2,
  settings,
  allowAttemptToReconnect: true,
);

2.2.4

• Added Windows-1252 (win1252) support to CoreConnection.

final con = CoreConnection(
  'user',
  database: 'db',
  host: 'localhost',
  port: 5432,
  password: 'pass',
  textCharset: 'win1252',
);

2.2.3

• Fixed a serious intermittent error when executing prepared statements for SELECT queries that return large amounts of data.

2.2.2

• Fixed query-error and database-restart handling bugs.

2.2.1

• Fixed bugs in queryUnnamed and prepareStatement.

2.2.0

• Implemented ResultStream and Results for data returned by queryUnnamed and querySimple.

2.1.0

• Added placeholder-style selection to queryUnnamed and prepareStatement, including PHP PDO-style question-mark parameters.

queryUnnamed(
  'SELECT * FROM book WHERE title = ? AND code = ?',
  ['title', 10],
  placeholderIdentifier: PlaceholderIdentifier.onlyQuestionMark,
);

2.0.0

• Migrated the package to null safety.

1.0.1

• Fixed an insert bug and implemented queryUnnamed for unnamed prepared statement execution.

1.0.0

• Initial version.