sq/drivers/csv/csv.go
Neil O'Toole 7c56377b40
Struct alignment ()
* Field alignment
2024-01-27 00:11:24 -07:00

172 lines
4.3 KiB
Go

// Package csv implements the sq driver for CSV/TSV et al.
package csv
import (
"context"
"database/sql"
"log/slog"
"github.com/neilotoole/sq/libsq/core/errz"
"github.com/neilotoole/sq/libsq/core/lg"
"github.com/neilotoole/sq/libsq/core/lg/lga"
"github.com/neilotoole/sq/libsq/core/lg/lgm"
"github.com/neilotoole/sq/libsq/core/options"
"github.com/neilotoole/sq/libsq/driver"
"github.com/neilotoole/sq/libsq/files"
"github.com/neilotoole/sq/libsq/source"
"github.com/neilotoole/sq/libsq/source/drivertype"
"github.com/neilotoole/sq/libsq/source/location"
"github.com/neilotoole/sq/libsq/source/metadata"
)
// Provider implements driver.Provider.
type Provider struct {
Log *slog.Logger
Ingester driver.GripOpenIngester
Files *files.Files
}
// DriverFor implements driver.Provider.
func (d *Provider) DriverFor(typ drivertype.Type) (driver.Driver, error) {
switch typ { //nolint:exhaustive
case drivertype.CSV:
return &driveri{log: d.Log, typ: drivertype.CSV, ingester: d.Ingester, files: d.Files}, nil
case drivertype.TSV:
return &driveri{log: d.Log, typ: drivertype.TSV, ingester: d.Ingester, files: d.Files}, nil
}
return nil, errz.Errorf("unsupported driver type {%s}", typ)
}
// Driver implements driver.Driver.
type driveri struct {
ingester driver.GripOpenIngester
log *slog.Logger
files *files.Files
typ drivertype.Type
}
// DriverMetadata implements driver.Driver.
func (d *driveri) DriverMetadata() driver.Metadata {
md := driver.Metadata{Type: d.typ, Monotable: true}
if d.typ == drivertype.CSV {
md.Description = "Comma-Separated Values"
md.Doc = "https://en.wikipedia.org/wiki/Comma-separated_values"
} else {
md.Description = "Tab-Separated Values"
md.Doc = "https://en.wikipedia.org/wiki/Tab-separated_values"
}
return md
}
// Open implements driver.Driver.
func (d *driveri) Open(ctx context.Context, src *source.Source) (driver.Grip, error) {
log := lg.FromContext(ctx)
log.Debug(lgm.OpenSrc, lga.Src, src)
g := &grip{
log: d.log,
src: src,
files: d.files,
}
allowCache := driver.OptIngestCache.Get(options.FromContext(ctx))
ingestFn := func(ctx context.Context, destGrip driver.Grip) error {
log.Debug("Ingest func invoked", lga.Src, src)
return d.ingestCSV(ctx, src, destGrip)
}
var err error
if g.impl, err = d.ingester.OpenIngest(ctx, src, allowCache, ingestFn); err != nil {
return nil, err
}
return g, nil
}
// ValidateSource implements driver.Driver.
func (d *driveri) ValidateSource(src *source.Source) (*source.Source, error) {
if src.Type != d.typ {
return nil, errz.Errorf("expected driver type {%s} but got {%s}", d.typ, src.Type)
}
return src, nil
}
// Ping implements driver.Driver.
func (d *driveri) Ping(ctx context.Context, src *source.Source) error {
return d.files.Ping(ctx, src)
}
// grip implements driver.Grip.
type grip struct {
log *slog.Logger
src *source.Source
impl driver.Grip
files *files.Files
}
// DB implements driver.Grip.
func (g *grip) DB(ctx context.Context) (*sql.DB, error) {
return g.impl.DB(ctx)
}
// SQLDriver implements driver.Grip.
func (g *grip) SQLDriver() driver.SQLDriver {
return g.impl.SQLDriver()
}
// Source implements driver.Grip.
func (g *grip) Source() *source.Source {
return g.src
}
// TableMetadata implements driver.Grip.
func (g *grip) TableMetadata(ctx context.Context, tblName string) (*metadata.Table, error) {
if tblName != source.MonotableName {
return nil, errz.Errorf("table name should be %s for CSV/TSV etc., but got: %s",
source.MonotableName, tblName)
}
srcMeta, err := g.SourceMetadata(ctx, false)
if err != nil {
return nil, err
}
// There will only ever be one table for CSV.
return srcMeta.Tables[0], nil
}
// SourceMetadata implements driver.Grip.
func (g *grip) SourceMetadata(ctx context.Context, noSchema bool) (*metadata.Source, error) {
md, err := g.impl.SourceMetadata(ctx, noSchema)
if err != nil {
return nil, err
}
md.Handle = g.src.Handle
md.Location = g.src.Location
md.Driver = g.src.Type
md.Name, err = location.Filename(g.src.Location)
if err != nil {
return nil, err
}
md.Size, err = g.files.Filesize(ctx, g.src)
if err != nil {
return nil, err
}
md.FQName = md.Name
return md, nil
}
// Close implements driver.Grip.
func (g *grip) Close() error {
g.log.Debug(lgm.CloseDB, lga.Handle, g.src.Handle)
return errz.Err(g.impl.Close())
}