46 lines
1.2 KiB
Go
46 lines
1.2 KiB
Go
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package tdb
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import (
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"bytes"
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"errors"
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"fmt"
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)
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type uniqueConstraint struct {
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table *table
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field dbField
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index indexish
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}
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func newUniqueConstraint(table *table, index indexish, field dbField) (constraintish, error) {
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if table == nil {
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return nil, errors.New("[constraint] [unique] unable to create without table")
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}
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if index == nil {
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return nil, fmt.Errorf("[constraint] [unique] is only valid for indicies (to avoid full table scans)")
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}
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return &uniqueConstraint{
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table: table,
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field: field,
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index: index,
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}, nil
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}
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func (c *uniqueConstraint) validate(tx *Tx, pv dbPtrValue) error {
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indexedVals := c.index.indexedValues(pv)
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keyValue := c.index.keyValue(pv)
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for _, indexedVal := range indexedVals {
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if err := c.index.iteratePrefixed(tx, indexedVal, func(indexed []byte) (IterationSignal, error) {
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if !bytes.Equal(keyValue, indexed) {
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c.table.debugLogf("[constraint] [unique] violation: record with '%s'.'%s' = '%s' already exists (id: %s)", c.table.name, c.field.Name, indexedVal, indexed)
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return StopIteration, fmt.Errorf("[constraint] [unique] violation for field '%s'.'%s'", c.table.name, c.field.Name)
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}
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return StopIteration, nil
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}); err != nil {
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return err
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}
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}
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return nil
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}
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