public StorageNonNegativeInt64ReferenceKeyProviderBase(IStorageNonNegativeInt64ReferenceKeyProviderSettings settings)
{
settings.EnsureNotNull(nameof(settings)).EnsureReadOnly().EnsureValid();
//
InspectOfSettings(settings: settings);
//
_settings = settings;
_keyBuffer = ImmutableQueue <long> .Empty;
_keyBufferFillUpLock = new SemaphoreSlim(initialCount: 1, maxCount: 1);
_maxSizeOfKeyBuffer = Math.Min(val1: MaxSizeOfKeyBuffer, val2: settings.KeyBufferPreferredSize ?? DefaultSizeOfKeyBuffer);
}
protected virtual void InspectOfSettings(IStorageNonNegativeInt64ReferenceKeyProviderSettings settings)
{
}
public PgsqlNonNegativeInt64ReferenceKeyProvider(IServiceProvider serviceProvider, IStorageNonNegativeInt64ReferenceKeyProviderSettings settings)
: base(settings: settings)
{
serviceProvider.EnsureNotNull(nameof(serviceProvider));
settings.EntityTypeId.ArgProp($"{nameof(settings)}.{nameof(settings.EntityTypeId)}").EnsureHasMaxLength(maxLength: __EntityTypeIdMaxLength);
//
_serviceProvider = serviceProvider;
_instanceUid = Guid.NewGuid();
}
static async Task <TakeNextKeyResult> P_TryTakeNextKeyFromStoreAsync(IStorageNonNegativeInt64ReferenceKeyProviderSettings settings, int count, NpgsqlConnection storeConnection, Guid instanceUid, IContext ctx = default)
{
settings = settings.EnsureNotNull(nameof(settings)).AsReadOnly().EnsureValid().Value;
storeConnection.EnsureNotNull(nameof(storeConnection));
count.Arg(nameof(count)).EnsureNotLessThan(operand: 1);
//
var ct = ctx.Ct();
var caughtException = default(Exception);
var storeConnectionMustClosed = false;
var tempTableName = $@"""{instanceUid.ToString(format: "n", provider: CultureInfo.InvariantCulture)}_temp_table""";
var keysStorageObjectFullName = (settings.KeysStorageObjectSchemaName is null ? string.Empty : settings.KeysStorageObjectSchemaName + ".") + $@"""{settings.KeysStorageObjectName}""";
var paramlessPrepareStatementTemplates =
new List <string>(
collection:
new string[] {
// Открываем транзакцию
@"BEGIN;",
// Внутри транзакции снова получаем id транзакции, если он был инкрементирован, значит действительно окружающие транзакции отсутствуют. Иначе, если statement 'begin' был вызван ранее - инкрементирование не произойдет
@"DO
$$
DECLARE
previous_txid xid := (SELECT txid_current FROM {1});
current_txid xid := TXID_CURRENT();
BEGIN
IF previous_txid = current_txid THEN
RAISE 'Absence of any open transaction is required to perform this operation.';
END IF;
END;
$$ LANGUAGE plpgsql;"
});
var paramfulPrepareStatementTemplate =
// Передаем в данный запрос параметры, они будут записаны в таблицу. Результат работы запроса так же будет помещен в данную таблицу.
// ВАЖНО: имена параметров регистро-независимо связаны с именами передаваемых и получаемых параметров из кода clr. При правке параметров в данной команде, необходимо также изменить имена параметров в последующем коде. См. ниже '// Исполнение комманды с параметрами'.
//
@"DROP TABLE IF EXISTS {1};
CREATE TEMPORARY TABLE {1} AS
SELECT * FROM (
VALUES (txid_current(), @storeNodeId::uuid, @entityTypeId::text, @keyValueFirst::bigint, @keyValueLast::bigint, @takeKeysCount::bigint, null::bigint, null::bigint, FALSE::bool))
AS t (txid_current, storeNodeId, entityTypeId, keyValueFirst, keyValueLast, takeKeysCount, firstTakenKeyValue, lastTakenKeyValue, commit_txn);" ;
var bodyStatementTemplate =
@"DO
$$
DECLARE
var_storeNodeId UUID = (SELECT t.storeNodeId FROM {1} as t);
var_entityTypeId VARCHAR = (SELECT t.entityTypeId FROM {1} as t);
var_keyValueFirst BIGINT = (SELECT t.keyValueFirst FROM {1} as t);
var_keyValueLast BIGINT = (SELECT t.keyValueLast FROM {1} as t);
var_takeKeysCount INT = (SELECT t.takeKeysCount FROM {1} as t);
var_canTakeKeysCount INT;
var_generatorStateRef BIGINT;
var_previousKeyValue BIGINT;
BEGIN
IF var_keyValueFirst IS NULL THEN
RAISE 'No value for parameter ''@keyValueFirst''.';
END IF;
IF var_keyValueLast IS NULL THEN
RAISE 'No value for parameter ''@keyValueLast''.';
END IF;
IF var_keyValueLast < var_keyValueFirst THEN
RAISE 'No value for parameter ''@keyValueLast''.';
END IF;
IF var_takeKeysCount IS NULL THEN
RAISE 'No value for parameter ''@takeKeysCount''.';
END IF;
IF var_takeKeysCount < 1 OR (var_takeKeysCount - 1) > var_keyValueLast - var_keyValueFirst THEN
RAISE 'Invalid value of parameter ''@takeKeysCount''.';
END IF;
var_generatorStateRef = (SELECT
T.""Ref""
FROM
{0} T
WHERE
T.""StoreNodeId"" = var_storeNodeId
AND T.""EntityTypeId"" = var_entityTypeId);
IF (var_generatorStateRef IS NULL) THEN
INSERT INTO
{0} (
""Ref""
,""StoreNodeId""
,""EntityTypeId""
,""KeyValueFirst""
,""KeyValueLast""
,""PreviousKeyValue"")
VALUES (
var_keyValueFirst
,var_storeNodeId
,var_entityTypeId
,var_keyValueFirst
,var_keyValueLast
,var_keyValueFirst);
var_generatorStateRef = var_keyValueFirst;
ELSE
IF (NOT EXISTS(
SELECT
NULL
FROM
{0} T
WHERE
T.""Ref"" = var_generatorStateRef
AND T.""KeyValueFirst"" = var_keyValueFirst
AND T.""KeyValueLast"" = var_keyValueLast))
THEN
RAISE 'Specified values of parameters ''@keyValueFirst'' and ''@keyValueLast'' are not match to the according values of store node row.';
END IF;
END IF;
var_previousKeyValue = (
SELECT
""PreviousKeyValue""
FROM
{0}
WHERE
""Ref"" = var_generatorStateRef);
var_canTakeKeysCount = (
SELECT
MIN(T.KeysCount)
FROM (
VALUES
(var_takeKeysCount),
(CASE
WHEN var_previousKeyValue IS NULL THEN var_keyValueLast - var_keyValueFirst + 1
ELSE var_keyValueLast - var_previousKeyValue
END))
AS T (KeysCount));
IF var_canTakeKeysCount > 1 THEN
UPDATE {0} SET
""PreviousKeyValue"" =
CASE
WHEN var_previousKeyValue IS NULL THEN var_keyValueFirst + (var_canTakeKeysCount - 1)
ELSE var_previousKeyValue + var_canTakeKeysCount
END
WHERE
""Ref"" = var_generatorStateRef;
UPDATE {1} SET
firstTakenKeyValue =
CASE
WHEN var_previousKeyValue IS NULL THEN var_keyValueFirst
ELSE var_previousKeyValue + 1
END,
lastTakenKeyValue =
CASE
WHEN var_previousKeyValue IS NULL THEN var_keyValueFirst + (var_canTakeKeysCount - 1)
ELSE var_previousKeyValue + var_canTakeKeysCount
END,
commit_txn = TRUE;
END IF;
END;
$$ LANGUAGE plpgsql;" ;
//
try {
if (storeConnection.State != ConnectionState.Open)
{
await storeConnection.OpenAsync(cancellationToken : ct).ConfigureAwait(false);
storeConnectionMustClosed = true;
}
// Исполнение комманды с параметрами.
//
using (var storeCommand = createTextCommand()) {
storeCommand.CommandText = string.Format(format: paramfulPrepareStatementTemplate, arg0: keysStorageObjectFullName, arg1: tempTableName);
storeCommand
.Parameters
.AddRange(
values:
new NpgsqlParameter[] {
new NpgsqlParameter()
{
ParameterName = "@storeNodeId",
Direction = ParameterDirection.Input,
Value = settings.ScopeUid.Value
},
new NpgsqlParameter()
{
ParameterName = "@entityTypeId",
Direction = ParameterDirection.Input,
Value = settings.EntityTypeId,
Size = __EntityTypeIdMaxLength
},
new NpgsqlParameter()
{
ParameterName = "@keyValueFirst",
Direction = ParameterDirection.Input,
Value = settings.ScopeLowerKey.Value
},
new NpgsqlParameter()
{
ParameterName = "@keyValueLast",
Direction = ParameterDirection.Input,
Value = settings.ScopeUpperKey.Value
},
new NpgsqlParameter()
{
ParameterName = "@takeKeysCount",
Direction = ParameterDirection.Input,
Value = count
}
});
await storeCommand.ExecuteNonQueryAsync(cancellationToken : ct).ConfigureAwait(false);
}
// Исполнение комманд без параметров.
//
foreach (var commandStatementText in paramlessPrepareStatementTemplates)
{
using (var storeCommand = createTextCommand()) {
storeCommand.CommandText = string.Format(format: commandStatementText, arg0: keysStorageObjectFullName, arg1: tempTableName);
await storeCommand.ExecuteNonQueryAsync(cancellationToken : ct).ConfigureAwait(false);
}
}
// Исполнение тела (основной логики) запроса.
//
using (var storeCommand = createTextCommand()) {
storeCommand.CommandText = string.Format(format: bodyStatementTemplate, arg0: keysStorageObjectFullName, arg1: tempTableName);
await storeCommand.ExecuteNonQueryAsync(cancellationToken : ct).ConfigureAwait(false);
}
// Считываем результаты, сохраненные во временной таблице.
//
using (var storeCommand = createCommand(type: CommandType.TableDirect)) {
storeCommand.CommandText = tempTableName;
long?firstTakenKeyValue;
long?lastTakenKeyValue;
bool commit_txn;
var reader = await storeCommand.ExecuteReaderAsync(cancellationToken : ct).ConfigureAwait(false);
try {
if (await reader.ReadAsync(cancellationToken: ct).ConfigureAwait(false))
{
firstTakenKeyValue =
reader[nameof(firstTakenKeyValue)] == DBNull.Value
? throw new EonException($"Result table column '{nameof(firstTakenKeyValue)}' has invalid value '{nameof(DBNull.Value)}'.")
: (long?)reader[nameof(firstTakenKeyValue)];
lastTakenKeyValue =
reader[nameof(lastTakenKeyValue)] == DBNull.Value
? throw new EonException($"Result table column '{nameof(lastTakenKeyValue)}' has invalid value '{nameof(DBNull.Value)}'.") :
(long?)reader[nameof(lastTakenKeyValue)];
commit_txn =
reader[nameof(commit_txn)] == DBNull.Value
? throw new EonException($"Result table column '{nameof(commit_txn)}' has invalid value '{nameof(DBNull.Value)}'.")
: (bool)reader[nameof(commit_txn)];
}
else
{
throw new EonException(message: "Result table has no rows, but one expected.");
}
}
catch (IndexOutOfRangeException exception) {
throw new EonException(message: "Result table has no required column.", innerException: exception);
}
reader.Close();
if (commit_txn)
{
using (var storeCommand2 = createTextCommand()) {
storeCommand2.CommandText = "COMMIT;";
await storeCommand2.ExecuteNonQueryAsync(cancellationToken : ct).ConfigureAwait(false);
}
return(new TakeNextKeyResult(hasTaken: true, lowerTakenKey: firstTakenKeyValue, upperTakenKey: lastTakenKeyValue));
}
else
{
using (var storeCommand2 = createTextCommand()) {
storeCommand2.CommandText = "ROLLBACK;";
await storeCommand2.ExecuteNonQueryAsync(cancellationToken : ct).ConfigureAwait(false);
}
return(new TakeNextKeyResult(hasTaken: false, lowerTakenKey: null, upperTakenKey: null));
}
}
}
catch (Exception exception) {
caughtException = new EonException(message: "An error has occurred while trying to take next reference key(s) from storage.", innerException: exception);
throw caughtException;
}
finally {
if (storeConnectionMustClosed)
{
try {
storeConnection.Close();
}
catch (Exception secondException) {
throw new AggregateException(caughtException, secondException);
}
}
}
//
NpgsqlCommand createTextCommand()
=> createCommand(type: CommandType.Text);
NpgsqlCommand createCommand(CommandType type)
{
var command = storeConnection.CreateCommand();
command.CommandType = type;
command.CommandTimeout = settings.Storage.CommandExecutionTimeout.IsInfinite ? 0 : Math.Max(settings.Storage.CommandExecutionTimeout.Milliseconds / 1000, 1);
return(command);
}
}
