forked from pachyderm/pachyderm
/
sql.go
75 lines (69 loc) · 1.61 KB
/
sql.go
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package sql
import (
"bufio"
"fmt"
"io"
"strings"
)
// PGDumpReader parses a pgdump file into a header, rows, and a footer
type PGDumpReader struct {
Header []byte
Footer []byte
rd *bufio.Reader
}
// NewPGDumpReader creates a new PGDumpReader
func NewPGDumpReader(r *bufio.Reader) *PGDumpReader {
return &PGDumpReader{
rd: r,
}
}
// ReadRow parses the pgdump file and populates the header and the footer
// It returns EOF when done, and at that time both the Header and Footer will
// be populated. Both header and footer are required. If either are missing, an
// error is returned
func (r *PGDumpReader) ReadRow() ([]byte, error) {
if len(r.Header) == 0 {
err := r.readHeader()
if err != nil {
return nil, err
}
}
endLine := "\\.\n" // Trailing '\.' denotes the end of the row inserts
row, err := r.rd.ReadBytes('\n')
if string(row) == endLine {
r.Footer = append(r.Footer, row...)
err = r.readFooter()
row = nil // The endline is part of the footer
}
if err == io.EOF && len(r.Footer) == 0 {
return nil, fmt.Errorf("invalid pgdump - missing footer")
}
return row, err
}
func (r *PGDumpReader) readHeader() error {
done := false
for !done {
b, err := r.rd.ReadBytes('\n')
if err != nil {
if err == io.EOF {
return fmt.Errorf("invalid header - missing row inserts")
}
return err
}
if strings.HasPrefix(string(b), "COPY") {
done = true
}
r.Header = append(r.Header, b...)
}
return nil
}
func (r *PGDumpReader) readFooter() error {
for true {
b, err := r.rd.ReadBytes('\n')
r.Footer = append(r.Footer, b...)
if err != nil {
return err
}
}
return nil
}