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cmd: very basic REPL implementation (#97)
* cmd: very basic REPL implementation Basic REPL that only supports query executions.
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,134 @@ | ||
| package main | ||
|
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| import ( | ||
| "errors" | ||
| "io" | ||
| "os" | ||
| "path/filepath" | ||
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| "github.com/gitql/gitql" | ||
| gitqlgit "github.com/gitql/gitql/git" | ||
| "github.com/gitql/gitql/internal/format" | ||
| "github.com/gitql/gitql/sql" | ||
|
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| "gopkg.in/src-d/go-git.v4" | ||
| ) | ||
|
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| type cmdQueryBase struct { | ||
| cmd | ||
|
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| Path string `short:"p" long:"path" description:"Path where the git repository is located"` | ||
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| db sql.Database | ||
| e *gitql.Engine | ||
| } | ||
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| func (c *cmdQueryBase) validate() error { | ||
| var err error | ||
| c.Path, err = findDotGitFolder(c.Path) | ||
| return err | ||
| } | ||
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| func (c *cmdQueryBase) buildDatabase() error { | ||
| c.print("opening %q repository...\n", c.Path) | ||
|
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| var err error | ||
| r, err := git.NewFilesystemRepository(c.Path) | ||
| if err != nil { | ||
| return err | ||
| } | ||
|
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| empty, err := r.IsEmpty() | ||
| if err != nil { | ||
| return err | ||
| } | ||
|
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| if empty { | ||
| return errors.New("error: the repository is empty") | ||
| } | ||
|
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| head, err := r.Head() | ||
| if err != nil { | ||
| return err | ||
| } | ||
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| c.print("current HEAD %q\n", head.Hash()) | ||
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| name := filepath.Base(filepath.Join(c.Path, "..")) | ||
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| c.db = gitqlgit.NewDatabase(name, r) | ||
| c.e = gitql.New() | ||
| c.e.AddDatabase(c.db) | ||
|
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| return nil | ||
| } | ||
|
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| func (c *cmdQueryBase) executeQuery(sql string) (sql.Schema, sql.RowIter, error) { | ||
| c.print("executing %q at %q\n", sql, c.db.Name()) | ||
|
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| return c.e.Query(sql) | ||
| } | ||
|
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| func (c *cmdQueryBase) printQuery(schema sql.Schema, iter sql.RowIter, formatId string) error { | ||
| f, err := format.NewFormat(formatId, os.Stdout) | ||
| if err != nil { | ||
| return err | ||
| } | ||
|
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| headers := []string{} | ||
| for _, f := range schema { | ||
| headers = append(headers, f.Name) | ||
| } | ||
|
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| if err := f.WriteHeader(headers); err != nil { | ||
| return err | ||
| } | ||
|
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| for { | ||
| row, err := iter.Next() | ||
| if err == io.EOF { | ||
| break | ||
| } | ||
| if err != nil { | ||
| return err | ||
| } | ||
|
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| dataRow := make([]interface{}, len(row)) | ||
| for i := range row { | ||
| dataRow[i] = interface{}(row[i]) | ||
| } | ||
|
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| if err := f.Write(dataRow); err != nil { | ||
| return err | ||
| } | ||
| } | ||
|
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| return f.Close() | ||
| } | ||
|
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| func findDotGitFolder(path string) (string, error) { | ||
| if path == "" { | ||
| var err error | ||
| path, err = os.Getwd() | ||
| if err != nil { | ||
| return "", err | ||
| } | ||
| } | ||
|
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| git := filepath.Join(path, ".git") | ||
| _, err := os.Stat(git) | ||
| if err == nil { | ||
| return git, nil | ||
| } | ||
|
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| if !os.IsNotExist(err) { | ||
| return "", err | ||
| } | ||
|
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| next := filepath.Join(path, "..") | ||
| if next == path { | ||
| return "", errors.New("unable to find a git repository") | ||
| } | ||
|
|
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| return findDotGitFolder(next) | ||
| } |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,89 @@ | ||
| package main | ||
|
|
||
| import ( | ||
| "bufio" | ||
| "bytes" | ||
| "fmt" | ||
| "os" | ||
| "strings" | ||
| ) | ||
|
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| type CmdShell struct { | ||
| cmdQueryBase | ||
| } | ||
|
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| func (c *CmdShell) Execute(args []string) error { | ||
| if err := c.validate(); err != nil { | ||
| return err | ||
| } | ||
|
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| if err := c.buildDatabase(); err != nil { | ||
| return err | ||
| } | ||
|
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| fmt.Print(` | ||
| gitQL SHELL | ||
| ----------- | ||
| You must end your queries with ';' | ||
| `) | ||
|
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| s := bufio.NewScanner(os.Stdin) | ||
|
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| s.Split(scanQueries) | ||
|
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| for { | ||
| fmt.Print("!> ") | ||
|
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| if !s.Scan() { | ||
| break | ||
| } | ||
|
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| query := s.Text() | ||
|
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| query = strings.Replace(query, "\n", " ", -1) | ||
| query = strings.TrimSpace(query) | ||
|
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| fmt.Printf("\n--> Executing query: %s\n\n", query) | ||
|
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| schema, rowIter, err := c.executeQuery(query) | ||
| if err != nil { | ||
| c.printError(err) | ||
| continue | ||
| } | ||
|
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| if err := c.printQuery(schema, rowIter, "pretty"); err != nil { | ||
| c.printError(err) | ||
| } | ||
| } | ||
|
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| return s.Err() | ||
| } | ||
|
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| func (c *CmdShell) printError(err error) { | ||
| fmt.Printf("ERROR: %v\n\n", err) | ||
| } | ||
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| func scanQueries(data []byte, atEOF bool) (int, []byte, error) { | ||
| if atEOF && len(data) == 0 { | ||
| return 0, nil, nil | ||
| } | ||
| if i := bytes.IndexByte(data, ';'); i >= 0 { | ||
| // We have a full newline-terminated line. | ||
| return i + 1, dropCR(data[0:i]), nil | ||
| } | ||
| // If we're at EOF, we have a final, non-terminated line. Return it. | ||
| if atEOF { | ||
| return len(data), dropCR(data), nil | ||
| } | ||
| // Request more data. | ||
| return 0, nil, nil | ||
| } | ||
|
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| // dropCR drops a terminal \r from the data. | ||
| func dropCR(data []byte) []byte { | ||
| if len(data) > 0 && data[len(data)-1] == '\r' { | ||
| return data[0 : len(data)-1] | ||
| } | ||
| return data | ||
| } |