diff options
Diffstat (limited to '')
-rw-r--r-- | src/encoding/csv/example_test.go | 131 | ||||
-rw-r--r-- | src/encoding/csv/fuzz.go | 70 | ||||
-rw-r--r-- | src/encoding/csv/reader.go | 401 | ||||
-rw-r--r-- | src/encoding/csv/reader_test.go | 509 | ||||
-rw-r--r-- | src/encoding/csv/writer.go | 181 | ||||
-rw-r--r-- | src/encoding/csv/writer_test.go | 112 |
6 files changed, 1404 insertions, 0 deletions
diff --git a/src/encoding/csv/example_test.go b/src/encoding/csv/example_test.go new file mode 100644 index 0000000..dc227d4 --- /dev/null +++ b/src/encoding/csv/example_test.go @@ -0,0 +1,131 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package csv_test + +import ( + "encoding/csv" + "fmt" + "io" + "log" + "os" + "strings" +) + +func ExampleReader() { + in := `first_name,last_name,username +"Rob","Pike",rob +Ken,Thompson,ken +"Robert","Griesemer","gri" +` + r := csv.NewReader(strings.NewReader(in)) + + for { + record, err := r.Read() + if err == io.EOF { + break + } + if err != nil { + log.Fatal(err) + } + + fmt.Println(record) + } + // Output: + // [first_name last_name username] + // [Rob Pike rob] + // [Ken Thompson ken] + // [Robert Griesemer gri] +} + +// This example shows how csv.Reader can be configured to handle other +// types of CSV files. +func ExampleReader_options() { + in := `first_name;last_name;username +"Rob";"Pike";rob +# lines beginning with a # character are ignored +Ken;Thompson;ken +"Robert";"Griesemer";"gri" +` + r := csv.NewReader(strings.NewReader(in)) + r.Comma = ';' + r.Comment = '#' + + records, err := r.ReadAll() + if err != nil { + log.Fatal(err) + } + + fmt.Print(records) + // Output: + // [[first_name last_name username] [Rob Pike rob] [Ken Thompson ken] [Robert Griesemer gri]] +} + +func ExampleReader_ReadAll() { + in := `first_name,last_name,username +"Rob","Pike",rob +Ken,Thompson,ken +"Robert","Griesemer","gri" +` + r := csv.NewReader(strings.NewReader(in)) + + records, err := r.ReadAll() + if err != nil { + log.Fatal(err) + } + + fmt.Print(records) + // Output: + // [[first_name last_name username] [Rob Pike rob] [Ken Thompson ken] [Robert Griesemer gri]] +} + +func ExampleWriter() { + records := [][]string{ + {"first_name", "last_name", "username"}, + {"Rob", "Pike", "rob"}, + {"Ken", "Thompson", "ken"}, + {"Robert", "Griesemer", "gri"}, + } + + w := csv.NewWriter(os.Stdout) + + for _, record := range records { + if err := w.Write(record); err != nil { + log.Fatalln("error writing record to csv:", err) + } + } + + // Write any buffered data to the underlying writer (standard output). + w.Flush() + + if err := w.Error(); err != nil { + log.Fatal(err) + } + // Output: + // first_name,last_name,username + // Rob,Pike,rob + // Ken,Thompson,ken + // Robert,Griesemer,gri +} + +func ExampleWriter_WriteAll() { + records := [][]string{ + {"first_name", "last_name", "username"}, + {"Rob", "Pike", "rob"}, + {"Ken", "Thompson", "ken"}, + {"Robert", "Griesemer", "gri"}, + } + + w := csv.NewWriter(os.Stdout) + w.WriteAll(records) // calls Flush internally + + if err := w.Error(); err != nil { + log.Fatalln("error writing csv:", err) + } + // Output: + // first_name,last_name,username + // Rob,Pike,rob + // Ken,Thompson,ken + // Robert,Griesemer,gri +} diff --git a/src/encoding/csv/fuzz.go b/src/encoding/csv/fuzz.go new file mode 100644 index 0000000..8be21d5 --- /dev/null +++ b/src/encoding/csv/fuzz.go @@ -0,0 +1,70 @@ +// Copyright 2019 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build gofuzz + +package csv + +import ( + "bytes" + "fmt" + "reflect" +) + +func Fuzz(data []byte) int { + score := 0 + buf := new(bytes.Buffer) + + for _, tt := range []Reader{ + {}, + {Comma: ';'}, + {Comma: '\t'}, + {LazyQuotes: true}, + {TrimLeadingSpace: true}, + {Comment: '#'}, + {Comment: ';'}, + } { + r := NewReader(bytes.NewReader(data)) + r.Comma = tt.Comma + r.Comment = tt.Comment + r.LazyQuotes = tt.LazyQuotes + r.TrimLeadingSpace = tt.TrimLeadingSpace + + records, err := r.ReadAll() + if err != nil { + continue + } + score = 1 + + buf.Reset() + w := NewWriter(buf) + w.Comma = tt.Comma + err = w.WriteAll(records) + if err != nil { + fmt.Printf("writer = %#v\n", w) + fmt.Printf("records = %v\n", records) + panic(err) + } + + r = NewReader(buf) + r.Comma = tt.Comma + r.Comment = tt.Comment + r.LazyQuotes = tt.LazyQuotes + r.TrimLeadingSpace = tt.TrimLeadingSpace + result, err := r.ReadAll() + if err != nil { + fmt.Printf("reader = %#v\n", r) + fmt.Printf("records = %v\n", records) + panic(err) + } + + if !reflect.DeepEqual(records, result) { + fmt.Println("records = \n", records) + fmt.Println("result = \n", records) + panic("not equal") + } + } + + return score +} diff --git a/src/encoding/csv/reader.go b/src/encoding/csv/reader.go new file mode 100644 index 0000000..c40aa50 --- /dev/null +++ b/src/encoding/csv/reader.go @@ -0,0 +1,401 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package csv reads and writes comma-separated values (CSV) files. +// There are many kinds of CSV files; this package supports the format +// described in RFC 4180. +// +// A csv file contains zero or more records of one or more fields per record. +// Each record is separated by the newline character. The final record may +// optionally be followed by a newline character. +// +// field1,field2,field3 +// +// White space is considered part of a field. +// +// Carriage returns before newline characters are silently removed. +// +// Blank lines are ignored. A line with only whitespace characters (excluding +// the ending newline character) is not considered a blank line. +// +// Fields which start and stop with the quote character " are called +// quoted-fields. The beginning and ending quote are not part of the +// field. +// +// The source: +// +// normal string,"quoted-field" +// +// results in the fields +// +// {`normal string`, `quoted-field`} +// +// Within a quoted-field a quote character followed by a second quote +// character is considered a single quote. +// +// "the ""word"" is true","a ""quoted-field""" +// +// results in +// +// {`the "word" is true`, `a "quoted-field"`} +// +// Newlines and commas may be included in a quoted-field +// +// "Multi-line +// field","comma is ," +// +// results in +// +// {`Multi-line +// field`, `comma is ,`} +package csv + +import ( + "bufio" + "bytes" + "errors" + "fmt" + "io" + "unicode" + "unicode/utf8" +) + +// A ParseError is returned for parsing errors. +// Line numbers are 1-indexed and columns are 0-indexed. +type ParseError struct { + StartLine int // Line where the record starts + Line int // Line where the error occurred + Column int // Column (rune index) where the error occurred + Err error // The actual error +} + +func (e *ParseError) Error() string { + if e.Err == ErrFieldCount { + return fmt.Sprintf("record on line %d: %v", e.Line, e.Err) + } + if e.StartLine != e.Line { + return fmt.Sprintf("record on line %d; parse error on line %d, column %d: %v", e.StartLine, e.Line, e.Column, e.Err) + } + return fmt.Sprintf("parse error on line %d, column %d: %v", e.Line, e.Column, e.Err) +} + +func (e *ParseError) Unwrap() error { return e.Err } + +// These are the errors that can be returned in ParseError.Err. +var ( + ErrTrailingComma = errors.New("extra delimiter at end of line") // Deprecated: No longer used. + ErrBareQuote = errors.New("bare \" in non-quoted-field") + ErrQuote = errors.New("extraneous or missing \" in quoted-field") + ErrFieldCount = errors.New("wrong number of fields") +) + +var errInvalidDelim = errors.New("csv: invalid field or comment delimiter") + +func validDelim(r rune) bool { + return r != 0 && r != '"' && r != '\r' && r != '\n' && utf8.ValidRune(r) && r != utf8.RuneError +} + +// A Reader reads records from a CSV-encoded file. +// +// As returned by NewReader, a Reader expects input conforming to RFC 4180. +// The exported fields can be changed to customize the details before the +// first call to Read or ReadAll. +// +// The Reader converts all \r\n sequences in its input to plain \n, +// including in multiline field values, so that the returned data does +// not depend on which line-ending convention an input file uses. +type Reader struct { + // Comma is the field delimiter. + // It is set to comma (',') by NewReader. + // Comma must be a valid rune and must not be \r, \n, + // or the Unicode replacement character (0xFFFD). + Comma rune + + // Comment, if not 0, is the comment character. Lines beginning with the + // Comment character without preceding whitespace are ignored. + // With leading whitespace the Comment character becomes part of the + // field, even if TrimLeadingSpace is true. + // Comment must be a valid rune and must not be \r, \n, + // or the Unicode replacement character (0xFFFD). + // It must also not be equal to Comma. + Comment rune + + // FieldsPerRecord is the number of expected fields per record. + // If FieldsPerRecord is positive, Read requires each record to + // have the given number of fields. If FieldsPerRecord is 0, Read sets it to + // the number of fields in the first record, so that future records must + // have the same field count. If FieldsPerRecord is negative, no check is + // made and records may have a variable number of fields. + FieldsPerRecord int + + // If LazyQuotes is true, a quote may appear in an unquoted field and a + // non-doubled quote may appear in a quoted field. + LazyQuotes bool + + // If TrimLeadingSpace is true, leading white space in a field is ignored. + // This is done even if the field delimiter, Comma, is white space. + TrimLeadingSpace bool + + // ReuseRecord controls whether calls to Read may return a slice sharing + // the backing array of the previous call's returned slice for performance. + // By default, each call to Read returns newly allocated memory owned by the caller. + ReuseRecord bool + + TrailingComma bool // Deprecated: No longer used. + + r *bufio.Reader + + // numLine is the current line being read in the CSV file. + numLine int + + // rawBuffer is a line buffer only used by the readLine method. + rawBuffer []byte + + // recordBuffer holds the unescaped fields, one after another. + // The fields can be accessed by using the indexes in fieldIndexes. + // E.g., For the row `a,"b","c""d",e`, recordBuffer will contain `abc"de` + // and fieldIndexes will contain the indexes [1, 2, 5, 6]. + recordBuffer []byte + + // fieldIndexes is an index of fields inside recordBuffer. + // The i'th field ends at offset fieldIndexes[i] in recordBuffer. + fieldIndexes []int + + // lastRecord is a record cache and only used when ReuseRecord == true. + lastRecord []string +} + +// NewReader returns a new Reader that reads from r. +func NewReader(r io.Reader) *Reader { + return &Reader{ + Comma: ',', + r: bufio.NewReader(r), + } +} + +// Read reads one record (a slice of fields) from r. +// If the record has an unexpected number of fields, +// Read returns the record along with the error ErrFieldCount. +// Except for that case, Read always returns either a non-nil +// record or a non-nil error, but not both. +// If there is no data left to be read, Read returns nil, io.EOF. +// If ReuseRecord is true, the returned slice may be shared +// between multiple calls to Read. +func (r *Reader) Read() (record []string, err error) { + if r.ReuseRecord { + record, err = r.readRecord(r.lastRecord) + r.lastRecord = record + } else { + record, err = r.readRecord(nil) + } + return record, err +} + +// ReadAll reads all the remaining records from r. +// Each record is a slice of fields. +// A successful call returns err == nil, not err == io.EOF. Because ReadAll is +// defined to read until EOF, it does not treat end of file as an error to be +// reported. +func (r *Reader) ReadAll() (records [][]string, err error) { + for { + record, err := r.readRecord(nil) + if err == io.EOF { + return records, nil + } + if err != nil { + return nil, err + } + records = append(records, record) + } +} + +// readLine reads the next line (with the trailing endline). +// If EOF is hit without a trailing endline, it will be omitted. +// If some bytes were read, then the error is never io.EOF. +// The result is only valid until the next call to readLine. +func (r *Reader) readLine() ([]byte, error) { + line, err := r.r.ReadSlice('\n') + if err == bufio.ErrBufferFull { + r.rawBuffer = append(r.rawBuffer[:0], line...) + for err == bufio.ErrBufferFull { + line, err = r.r.ReadSlice('\n') + r.rawBuffer = append(r.rawBuffer, line...) + } + line = r.rawBuffer + } + if len(line) > 0 && err == io.EOF { + err = nil + // For backwards compatibility, drop trailing \r before EOF. + if line[len(line)-1] == '\r' { + line = line[:len(line)-1] + } + } + r.numLine++ + // Normalize \r\n to \n on all input lines. + if n := len(line); n >= 2 && line[n-2] == '\r' && line[n-1] == '\n' { + line[n-2] = '\n' + line = line[:n-1] + } + return line, err +} + +// lengthNL reports the number of bytes for the trailing \n. +func lengthNL(b []byte) int { + if len(b) > 0 && b[len(b)-1] == '\n' { + return 1 + } + return 0 +} + +// nextRune returns the next rune in b or utf8.RuneError. +func nextRune(b []byte) rune { + r, _ := utf8.DecodeRune(b) + return r +} + +func (r *Reader) readRecord(dst []string) ([]string, error) { + if r.Comma == r.Comment || !validDelim(r.Comma) || (r.Comment != 0 && !validDelim(r.Comment)) { + return nil, errInvalidDelim + } + + // Read line (automatically skipping past empty lines and any comments). + var line, fullLine []byte + var errRead error + for errRead == nil { + line, errRead = r.readLine() + if r.Comment != 0 && nextRune(line) == r.Comment { + line = nil + continue // Skip comment lines + } + if errRead == nil && len(line) == lengthNL(line) { + line = nil + continue // Skip empty lines + } + fullLine = line + break + } + if errRead == io.EOF { + return nil, errRead + } + + // Parse each field in the record. + var err error + const quoteLen = len(`"`) + commaLen := utf8.RuneLen(r.Comma) + recLine := r.numLine // Starting line for record + r.recordBuffer = r.recordBuffer[:0] + r.fieldIndexes = r.fieldIndexes[:0] +parseField: + for { + if r.TrimLeadingSpace { + line = bytes.TrimLeftFunc(line, unicode.IsSpace) + } + if len(line) == 0 || line[0] != '"' { + // Non-quoted string field + i := bytes.IndexRune(line, r.Comma) + field := line + if i >= 0 { + field = field[:i] + } else { + field = field[:len(field)-lengthNL(field)] + } + // Check to make sure a quote does not appear in field. + if !r.LazyQuotes { + if j := bytes.IndexByte(field, '"'); j >= 0 { + col := utf8.RuneCount(fullLine[:len(fullLine)-len(line[j:])]) + err = &ParseError{StartLine: recLine, Line: r.numLine, Column: col, Err: ErrBareQuote} + break parseField + } + } + r.recordBuffer = append(r.recordBuffer, field...) + r.fieldIndexes = append(r.fieldIndexes, len(r.recordBuffer)) + if i >= 0 { + line = line[i+commaLen:] + continue parseField + } + break parseField + } else { + // Quoted string field + line = line[quoteLen:] + for { + i := bytes.IndexByte(line, '"') + if i >= 0 { + // Hit next quote. + r.recordBuffer = append(r.recordBuffer, line[:i]...) + line = line[i+quoteLen:] + switch rn := nextRune(line); { + case rn == '"': + // `""` sequence (append quote). + r.recordBuffer = append(r.recordBuffer, '"') + line = line[quoteLen:] + case rn == r.Comma: + // `",` sequence (end of field). + line = line[commaLen:] + r.fieldIndexes = append(r.fieldIndexes, len(r.recordBuffer)) + continue parseField + case lengthNL(line) == len(line): + // `"\n` sequence (end of line). + r.fieldIndexes = append(r.fieldIndexes, len(r.recordBuffer)) + break parseField + case r.LazyQuotes: + // `"` sequence (bare quote). + r.recordBuffer = append(r.recordBuffer, '"') + default: + // `"*` sequence (invalid non-escaped quote). + col := utf8.RuneCount(fullLine[:len(fullLine)-len(line)-quoteLen]) + err = &ParseError{StartLine: recLine, Line: r.numLine, Column: col, Err: ErrQuote} + break parseField + } + } else if len(line) > 0 { + // Hit end of line (copy all data so far). + r.recordBuffer = append(r.recordBuffer, line...) + if errRead != nil { + break parseField + } + line, errRead = r.readLine() + if errRead == io.EOF { + errRead = nil + } + fullLine = line + } else { + // Abrupt end of file (EOF or error). + if !r.LazyQuotes && errRead == nil { + col := utf8.RuneCount(fullLine) + err = &ParseError{StartLine: recLine, Line: r.numLine, Column: col, Err: ErrQuote} + break parseField + } + r.fieldIndexes = append(r.fieldIndexes, len(r.recordBuffer)) + break parseField + } + } + } + } + if err == nil { + err = errRead + } + + // Create a single string and create slices out of it. + // This pins the memory of the fields together, but allocates once. + str := string(r.recordBuffer) // Convert to string once to batch allocations + dst = dst[:0] + if cap(dst) < len(r.fieldIndexes) { + dst = make([]string, len(r.fieldIndexes)) + } + dst = dst[:len(r.fieldIndexes)] + var preIdx int + for i, idx := range r.fieldIndexes { + dst[i] = str[preIdx:idx] + preIdx = idx + } + + // Check or update the expected fields per record. + if r.FieldsPerRecord > 0 { + if len(dst) != r.FieldsPerRecord && err == nil { + err = &ParseError{StartLine: recLine, Line: recLine, Err: ErrFieldCount} + } + } else if r.FieldsPerRecord == 0 { + r.FieldsPerRecord = len(dst) + } + return dst, err +} diff --git a/src/encoding/csv/reader_test.go b/src/encoding/csv/reader_test.go new file mode 100644 index 0000000..5121791 --- /dev/null +++ b/src/encoding/csv/reader_test.go @@ -0,0 +1,509 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package csv + +import ( + "io" + "reflect" + "strings" + "testing" + "unicode/utf8" +) + +func TestRead(t *testing.T) { + tests := []struct { + Name string + Input string + Output [][]string + Error error + + // These fields are copied into the Reader + Comma rune + Comment rune + UseFieldsPerRecord bool // false (default) means FieldsPerRecord is -1 + FieldsPerRecord int + LazyQuotes bool + TrimLeadingSpace bool + ReuseRecord bool + }{{ + Name: "Simple", + Input: "a,b,c\n", + Output: [][]string{{"a", "b", "c"}}, + }, { + Name: "CRLF", + Input: "a,b\r\nc,d\r\n", + Output: [][]string{{"a", "b"}, {"c", "d"}}, + }, { + Name: "BareCR", + Input: "a,b\rc,d\r\n", + Output: [][]string{{"a", "b\rc", "d"}}, + }, { + Name: "RFC4180test", + Input: `#field1,field2,field3 +"aaa","bb +b","ccc" +"a,a","b""bb","ccc" +zzz,yyy,xxx +`, + Output: [][]string{ + {"#field1", "field2", "field3"}, + {"aaa", "bb\nb", "ccc"}, + {"a,a", `b"bb`, "ccc"}, + {"zzz", "yyy", "xxx"}, + }, + UseFieldsPerRecord: true, + FieldsPerRecord: 0, + }, { + Name: "NoEOLTest", + Input: "a,b,c", + Output: [][]string{{"a", "b", "c"}}, + }, { + Name: "Semicolon", + Input: "a;b;c\n", + Output: [][]string{{"a", "b", "c"}}, + Comma: ';', + }, { + Name: "MultiLine", + Input: `"two +line","one line","three +line +field"`, + Output: [][]string{{"two\nline", "one line", "three\nline\nfield"}}, + }, { + Name: "BlankLine", + Input: "a,b,c\n\nd,e,f\n\n", + Output: [][]string{ + {"a", "b", "c"}, + {"d", "e", "f"}, + }, + }, { + Name: "BlankLineFieldCount", + Input: "a,b,c\n\nd,e,f\n\n", + Output: [][]string{ + {"a", "b", "c"}, + {"d", "e", "f"}, + }, + UseFieldsPerRecord: true, + FieldsPerRecord: 0, + }, { + Name: "TrimSpace", + Input: " a, b, c\n", + Output: [][]string{{"a", "b", "c"}}, + TrimLeadingSpace: true, + }, { + Name: "LeadingSpace", + Input: " a, b, c\n", + Output: [][]string{{" a", " b", " c"}}, + }, { + Name: "Comment", + Input: "#1,2,3\na,b,c\n#comment", + Output: [][]string{{"a", "b", "c"}}, + Comment: '#', + }, { + Name: "NoComment", + Input: "#1,2,3\na,b,c", + Output: [][]string{{"#1", "2", "3"}, {"a", "b", "c"}}, + }, { + Name: "LazyQuotes", + Input: `a "word","1"2",a","b`, + Output: [][]string{{`a "word"`, `1"2`, `a"`, `b`}}, + LazyQuotes: true, + }, { + Name: "BareQuotes", + Input: `a "word","1"2",a"`, + Output: [][]string{{`a "word"`, `1"2`, `a"`}}, + LazyQuotes: true, + }, { + Name: "BareDoubleQuotes", + Input: `a""b,c`, + Output: [][]string{{`a""b`, `c`}}, + LazyQuotes: true, + }, { + Name: "BadDoubleQuotes", + Input: `a""b,c`, + Error: &ParseError{StartLine: 1, Line: 1, Column: 1, Err: ErrBareQuote}, + }, { + Name: "TrimQuote", + Input: ` "a"," b",c`, + Output: [][]string{{"a", " b", "c"}}, + TrimLeadingSpace: true, + }, { + Name: "BadBareQuote", + Input: `a "word","b"`, + Error: &ParseError{StartLine: 1, Line: 1, Column: 2, Err: ErrBareQuote}, + }, { + Name: "BadTrailingQuote", + Input: `"a word",b"`, + Error: &ParseError{StartLine: 1, Line: 1, Column: 10, Err: ErrBareQuote}, + }, { + Name: "ExtraneousQuote", + Input: `"a "word","b"`, + Error: &ParseError{StartLine: 1, Line: 1, Column: 3, Err: ErrQuote}, + }, { + Name: "BadFieldCount", + Input: "a,b,c\nd,e", + Error: &ParseError{StartLine: 2, Line: 2, Err: ErrFieldCount}, + UseFieldsPerRecord: true, + FieldsPerRecord: 0, + }, { + Name: "BadFieldCount1", + Input: `a,b,c`, + Error: &ParseError{StartLine: 1, Line: 1, Err: ErrFieldCount}, + UseFieldsPerRecord: true, + FieldsPerRecord: 2, + }, { + Name: "FieldCount", + Input: "a,b,c\nd,e", + Output: [][]string{{"a", "b", "c"}, {"d", "e"}}, + }, { + Name: "TrailingCommaEOF", + Input: "a,b,c,", + Output: [][]string{{"a", "b", "c", ""}}, + }, { + Name: "TrailingCommaEOL", + Input: "a,b,c,\n", + Output: [][]string{{"a", "b", "c", ""}}, + }, { + Name: "TrailingCommaSpaceEOF", + Input: "a,b,c, ", + Output: [][]string{{"a", "b", "c", ""}}, + TrimLeadingSpace: true, + }, { + Name: "TrailingCommaSpaceEOL", + Input: "a,b,c, \n", + Output: [][]string{{"a", "b", "c", ""}}, + TrimLeadingSpace: true, + }, { + Name: "TrailingCommaLine3", + Input: "a,b,c\nd,e,f\ng,hi,", + Output: [][]string{{"a", "b", "c"}, {"d", "e", "f"}, {"g", "hi", ""}}, + TrimLeadingSpace: true, + }, { + Name: "NotTrailingComma3", + Input: "a,b,c, \n", + Output: [][]string{{"a", "b", "c", " "}}, + }, { + Name: "CommaFieldTest", + Input: `x,y,z,w +x,y,z, +x,y,, +x,,, +,,, +"x","y","z","w" +"x","y","z","" +"x","y","","" +"x","","","" +"","","","" +`, + Output: [][]string{ + {"x", "y", "z", "w"}, + {"x", "y", "z", ""}, + {"x", "y", "", ""}, + {"x", "", "", ""}, + {"", "", "", ""}, + {"x", "y", "z", "w"}, + {"x", "y", "z", ""}, + {"x", "y", "", ""}, + {"x", "", "", ""}, + {"", "", "", ""}, + }, + }, { + Name: "TrailingCommaIneffective1", + Input: "a,b,\nc,d,e", + Output: [][]string{ + {"a", "b", ""}, + {"c", "d", "e"}, + }, + TrimLeadingSpace: true, + }, { + Name: "ReadAllReuseRecord", + Input: "a,b\nc,d", + Output: [][]string{ + {"a", "b"}, + {"c", "d"}, + }, + ReuseRecord: true, + }, { + Name: "StartLine1", // Issue 19019 + Input: "a,\"b\nc\"d,e", + Error: &ParseError{StartLine: 1, Line: 2, Column: 1, Err: ErrQuote}, + }, { + Name: "StartLine2", + Input: "a,b\n\"d\n\n,e", + Error: &ParseError{StartLine: 2, Line: 5, Column: 0, Err: ErrQuote}, + }, { + Name: "CRLFInQuotedField", // Issue 21201 + Input: "A,\"Hello\r\nHi\",B\r\n", + Output: [][]string{ + {"A", "Hello\nHi", "B"}, + }, + }, { + Name: "BinaryBlobField", // Issue 19410 + Input: "x09\x41\xb4\x1c,aktau", + Output: [][]string{{"x09A\xb4\x1c", "aktau"}}, + }, { + Name: "TrailingCR", + Input: "field1,field2\r", + Output: [][]string{{"field1", "field2"}}, + }, { + Name: "QuotedTrailingCR", + Input: "\"field\"\r", + Output: [][]string{{"field"}}, + }, { + Name: "QuotedTrailingCRCR", + Input: "\"field\"\r\r", + Error: &ParseError{StartLine: 1, Line: 1, Column: 6, Err: ErrQuote}, + }, { + Name: "FieldCR", + Input: "field\rfield\r", + Output: [][]string{{"field\rfield"}}, + }, { + Name: "FieldCRCR", + Input: "field\r\rfield\r\r", + Output: [][]string{{"field\r\rfield\r"}}, + }, { + Name: "FieldCRCRLF", + Input: "field\r\r\nfield\r\r\n", + Output: [][]string{{"field\r"}, {"field\r"}}, + }, { + Name: "FieldCRCRLFCR", + Input: "field\r\r\n\rfield\r\r\n\r", + Output: [][]string{{"field\r"}, {"\rfield\r"}}, + }, { + Name: "FieldCRCRLFCRCR", + Input: "field\r\r\n\r\rfield\r\r\n\r\r", + Output: [][]string{{"field\r"}, {"\r\rfield\r"}, {"\r"}}, + }, { + Name: "MultiFieldCRCRLFCRCR", + Input: "field1,field2\r\r\n\r\rfield1,field2\r\r\n\r\r,", + Output: [][]string{ + {"field1", "field2\r"}, + {"\r\rfield1", "field2\r"}, + {"\r\r", ""}, + }, + }, { + Name: "NonASCIICommaAndComment", + Input: "a£b,c£ \td,e\n€ comment\n", + Output: [][]string{{"a", "b,c", "d,e"}}, + TrimLeadingSpace: true, + Comma: '£', + Comment: '€', + }, { + Name: "NonASCIICommaAndCommentWithQuotes", + Input: "a€\" b,\"€ c\nλ comment\n", + Output: [][]string{{"a", " b,", " c"}}, + Comma: '€', + Comment: 'λ', + }, { + // λ and θ start with the same byte. + // This tests that the parser doesn't confuse such characters. + Name: "NonASCIICommaConfusion", + Input: "\"abθcd\"λefθgh", + Output: [][]string{{"abθcd", "efθgh"}}, + Comma: 'λ', + Comment: '€', + }, { + Name: "NonASCIICommentConfusion", + Input: "λ\nλ\nθ\nλ\n", + Output: [][]string{{"λ"}, {"λ"}, {"λ"}}, + Comment: 'θ', + }, { + Name: "QuotedFieldMultipleLF", + Input: "\"\n\n\n\n\"", + Output: [][]string{{"\n\n\n\n"}}, + }, { + Name: "MultipleCRLF", + Input: "\r\n\r\n\r\n\r\n", + }, { + // The implementation may read each line in several chunks if it doesn't fit entirely + // in the read buffer, so we should test the code to handle that condition. + Name: "HugeLines", + Input: strings.Repeat("#ignore\n", 10000) + strings.Repeat("@", 5000) + "," + strings.Repeat("*", 5000), + Output: [][]string{{strings.Repeat("@", 5000), strings.Repeat("*", 5000)}}, + Comment: '#', + }, { + Name: "QuoteWithTrailingCRLF", + Input: "\"foo\"bar\"\r\n", + Error: &ParseError{StartLine: 1, Line: 1, Column: 4, Err: ErrQuote}, + }, { + Name: "LazyQuoteWithTrailingCRLF", + Input: "\"foo\"bar\"\r\n", + Output: [][]string{{`foo"bar`}}, + LazyQuotes: true, + }, { + Name: "DoubleQuoteWithTrailingCRLF", + Input: "\"foo\"\"bar\"\r\n", + Output: [][]string{{`foo"bar`}}, + }, { + Name: "EvenQuotes", + Input: `""""""""`, + Output: [][]string{{`"""`}}, + }, { + Name: "OddQuotes", + Input: `"""""""`, + Error: &ParseError{StartLine: 1, Line: 1, Column: 7, Err: ErrQuote}, + }, { + Name: "LazyOddQuotes", + Input: `"""""""`, + Output: [][]string{{`"""`}}, + LazyQuotes: true, + }, { + Name: "BadComma1", + Comma: '\n', + Error: errInvalidDelim, + }, { + Name: "BadComma2", + Comma: '\r', + Error: errInvalidDelim, + }, { + Name: "BadComma3", + Comma: '"', + Error: errInvalidDelim, + }, { + Name: "BadComma4", + Comma: utf8.RuneError, + Error: errInvalidDelim, + }, { + Name: "BadComment1", + Comment: '\n', + Error: errInvalidDelim, + }, { + Name: "BadComment2", + Comment: '\r', + Error: errInvalidDelim, + }, { + Name: "BadComment3", + Comment: utf8.RuneError, + Error: errInvalidDelim, + }, { + Name: "BadCommaComment", + Comma: 'X', + Comment: 'X', + Error: errInvalidDelim, + }} + + for _, tt := range tests { + t.Run(tt.Name, func(t *testing.T) { + r := NewReader(strings.NewReader(tt.Input)) + + if tt.Comma != 0 { + r.Comma = tt.Comma + } + r.Comment = tt.Comment + if tt.UseFieldsPerRecord { + r.FieldsPerRecord = tt.FieldsPerRecord + } else { + r.FieldsPerRecord = -1 + } + r.LazyQuotes = tt.LazyQuotes + r.TrimLeadingSpace = tt.TrimLeadingSpace + r.ReuseRecord = tt.ReuseRecord + + out, err := r.ReadAll() + if !reflect.DeepEqual(err, tt.Error) { + t.Errorf("ReadAll() error:\ngot %v\nwant %v", err, tt.Error) + } else if !reflect.DeepEqual(out, tt.Output) { + t.Errorf("ReadAll() output:\ngot %q\nwant %q", out, tt.Output) + } + }) + } +} + +// nTimes is an io.Reader which yields the string s n times. +type nTimes struct { + s string + n int + off int +} + +func (r *nTimes) Read(p []byte) (n int, err error) { + for { + if r.n <= 0 || r.s == "" { + return n, io.EOF + } + n0 := copy(p, r.s[r.off:]) + p = p[n0:] + n += n0 + r.off += n0 + if r.off == len(r.s) { + r.off = 0 + r.n-- + } + if len(p) == 0 { + return + } + } +} + +// benchmarkRead measures reading the provided CSV rows data. +// initReader, if non-nil, modifies the Reader before it's used. +func benchmarkRead(b *testing.B, initReader func(*Reader), rows string) { + b.ReportAllocs() + r := NewReader(&nTimes{s: rows, n: b.N}) + if initReader != nil { + initReader(r) + } + for { + _, err := r.Read() + if err == io.EOF { + break + } + if err != nil { + b.Fatal(err) + } + } +} + +const benchmarkCSVData = `x,y,z,w +x,y,z, +x,y,, +x,,, +,,, +"x","y","z","w" +"x","y","z","" +"x","y","","" +"x","","","" +"","","","" +` + +func BenchmarkRead(b *testing.B) { + benchmarkRead(b, nil, benchmarkCSVData) +} + +func BenchmarkReadWithFieldsPerRecord(b *testing.B) { + benchmarkRead(b, func(r *Reader) { r.FieldsPerRecord = 4 }, benchmarkCSVData) +} + +func BenchmarkReadWithoutFieldsPerRecord(b *testing.B) { + benchmarkRead(b, func(r *Reader) { r.FieldsPerRecord = -1 }, benchmarkCSVData) +} + +func BenchmarkReadLargeFields(b *testing.B) { + benchmarkRead(b, nil, strings.Repeat(`xxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +xxxxxxxxxxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvv +,,zzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +`, 3)) +} + +func BenchmarkReadReuseRecord(b *testing.B) { + benchmarkRead(b, func(r *Reader) { r.ReuseRecord = true }, benchmarkCSVData) +} + +func BenchmarkReadReuseRecordWithFieldsPerRecord(b *testing.B) { + benchmarkRead(b, func(r *Reader) { r.ReuseRecord = true; r.FieldsPerRecord = 4 }, benchmarkCSVData) +} + +func BenchmarkReadReuseRecordWithoutFieldsPerRecord(b *testing.B) { + benchmarkRead(b, func(r *Reader) { r.ReuseRecord = true; r.FieldsPerRecord = -1 }, benchmarkCSVData) +} + +func BenchmarkReadReuseRecordLargeFields(b *testing.B) { + benchmarkRead(b, func(r *Reader) { r.ReuseRecord = true }, strings.Repeat(`xxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +xxxxxxxxxxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvv +,,zzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +`, 3)) +} diff --git a/src/encoding/csv/writer.go b/src/encoding/csv/writer.go new file mode 100644 index 0000000..ac64b4d --- /dev/null +++ b/src/encoding/csv/writer.go @@ -0,0 +1,181 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package csv + +import ( + "bufio" + "io" + "strings" + "unicode" + "unicode/utf8" +) + +// A Writer writes records using CSV encoding. +// +// As returned by NewWriter, a Writer writes records terminated by a +// newline and uses ',' as the field delimiter. The exported fields can be +// changed to customize the details before the first call to Write or WriteAll. +// +// Comma is the field delimiter. +// +// If UseCRLF is true, the Writer ends each output line with \r\n instead of \n. +// +// The writes of individual records are buffered. +// After all data has been written, the client should call the +// Flush method to guarantee all data has been forwarded to +// the underlying io.Writer. Any errors that occurred should +// be checked by calling the Error method. +type Writer struct { + Comma rune // Field delimiter (set to ',' by NewWriter) + UseCRLF bool // True to use \r\n as the line terminator + w *bufio.Writer +} + +// NewWriter returns a new Writer that writes to w. +func NewWriter(w io.Writer) *Writer { + return &Writer{ + Comma: ',', + w: bufio.NewWriter(w), + } +} + +// Write writes a single CSV record to w along with any necessary quoting. +// A record is a slice of strings with each string being one field. +// Writes are buffered, so Flush must eventually be called to ensure +// that the record is written to the underlying io.Writer. +func (w *Writer) Write(record []string) error { + if !validDelim(w.Comma) { + return errInvalidDelim + } + + for n, field := range record { + if n > 0 { + if _, err := w.w.WriteRune(w.Comma); err != nil { + return err + } + } + + // If we don't have to have a quoted field then just + // write out the field and continue to the next field. + if !w.fieldNeedsQuotes(field) { + if _, err := w.w.WriteString(field); err != nil { + return err + } + continue + } + + if err := w.w.WriteByte('"'); err != nil { + return err + } + for len(field) > 0 { + // Search for special characters. + i := strings.IndexAny(field, "\"\r\n") + if i < 0 { + i = len(field) + } + + // Copy verbatim everything before the special character. + if _, err := w.w.WriteString(field[:i]); err != nil { + return err + } + field = field[i:] + + // Encode the special character. + if len(field) > 0 { + var err error + switch field[0] { + case '"': + _, err = w.w.WriteString(`""`) + case '\r': + if !w.UseCRLF { + err = w.w.WriteByte('\r') + } + case '\n': + if w.UseCRLF { + _, err = w.w.WriteString("\r\n") + } else { + err = w.w.WriteByte('\n') + } + } + field = field[1:] + if err != nil { + return err + } + } + } + if err := w.w.WriteByte('"'); err != nil { + return err + } + } + var err error + if w.UseCRLF { + _, err = w.w.WriteString("\r\n") + } else { + err = w.w.WriteByte('\n') + } + return err +} + +// Flush writes any buffered data to the underlying io.Writer. +// To check if an error occurred during the Flush, call Error. +func (w *Writer) Flush() { + w.w.Flush() +} + +// Error reports any error that has occurred during a previous Write or Flush. +func (w *Writer) Error() error { + _, err := w.w.Write(nil) + return err +} + +// WriteAll writes multiple CSV records to w using Write and then calls Flush, +// returning any error from the Flush. +func (w *Writer) WriteAll(records [][]string) error { + for _, record := range records { + err := w.Write(record) + if err != nil { + return err + } + } + return w.w.Flush() +} + +// fieldNeedsQuotes reports whether our field must be enclosed in quotes. +// Fields with a Comma, fields with a quote or newline, and +// fields which start with a space must be enclosed in quotes. +// We used to quote empty strings, but we do not anymore (as of Go 1.4). +// The two representations should be equivalent, but Postgres distinguishes +// quoted vs non-quoted empty string during database imports, and it has +// an option to force the quoted behavior for non-quoted CSV but it has +// no option to force the non-quoted behavior for quoted CSV, making +// CSV with quoted empty strings strictly less useful. +// Not quoting the empty string also makes this package match the behavior +// of Microsoft Excel and Google Drive. +// For Postgres, quote the data terminating string `\.`. +func (w *Writer) fieldNeedsQuotes(field string) bool { + if field == "" { + return false + } + + if field == `\.` { + return true + } + + if w.Comma < utf8.RuneSelf { + for i := 0; i < len(field); i++ { + c := field[i] + if c == '\n' || c == '\r' || c == '"' || c == byte(w.Comma) { + return true + } + } + } else { + if strings.ContainsRune(field, w.Comma) || strings.ContainsAny(field, "\"\r\n") { + return true + } + } + + r1, _ := utf8.DecodeRuneInString(field) + return unicode.IsSpace(r1) +} diff --git a/src/encoding/csv/writer_test.go b/src/encoding/csv/writer_test.go new file mode 100644 index 0000000..ab28b0d --- /dev/null +++ b/src/encoding/csv/writer_test.go @@ -0,0 +1,112 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package csv + +import ( + "bytes" + "errors" + "testing" +) + +var writeTests = []struct { + Input [][]string + Output string + Error error + UseCRLF bool + Comma rune +}{ + {Input: [][]string{{"abc"}}, Output: "abc\n"}, + {Input: [][]string{{"abc"}}, Output: "abc\r\n", UseCRLF: true}, + {Input: [][]string{{`"abc"`}}, Output: `"""abc"""` + "\n"}, + {Input: [][]string{{`a"b`}}, Output: `"a""b"` + "\n"}, + {Input: [][]string{{`"a"b"`}}, Output: `"""a""b"""` + "\n"}, + {Input: [][]string{{" abc"}}, Output: `" abc"` + "\n"}, + {Input: [][]string{{"abc,def"}}, Output: `"abc,def"` + "\n"}, + {Input: [][]string{{"abc", "def"}}, Output: "abc,def\n"}, + {Input: [][]string{{"abc"}, {"def"}}, Output: "abc\ndef\n"}, + {Input: [][]string{{"abc\ndef"}}, Output: "\"abc\ndef\"\n"}, + {Input: [][]string{{"abc\ndef"}}, Output: "\"abc\r\ndef\"\r\n", UseCRLF: true}, + {Input: [][]string{{"abc\rdef"}}, Output: "\"abcdef\"\r\n", UseCRLF: true}, + {Input: [][]string{{"abc\rdef"}}, Output: "\"abc\rdef\"\n", UseCRLF: false}, + {Input: [][]string{{""}}, Output: "\n"}, + {Input: [][]string{{"", ""}}, Output: ",\n"}, + {Input: [][]string{{"", "", ""}}, Output: ",,\n"}, + {Input: [][]string{{"", "", "a"}}, Output: ",,a\n"}, + {Input: [][]string{{"", "a", ""}}, Output: ",a,\n"}, + {Input: [][]string{{"", "a", "a"}}, Output: ",a,a\n"}, + {Input: [][]string{{"a", "", ""}}, Output: "a,,\n"}, + {Input: [][]string{{"a", "", "a"}}, Output: "a,,a\n"}, + {Input: [][]string{{"a", "a", ""}}, Output: "a,a,\n"}, + {Input: [][]string{{"a", "a", "a"}}, Output: "a,a,a\n"}, + {Input: [][]string{{`\.`}}, Output: "\"\\.\"\n"}, + {Input: [][]string{{"x09\x41\xb4\x1c", "aktau"}}, Output: "x09\x41\xb4\x1c,aktau\n"}, + {Input: [][]string{{",x09\x41\xb4\x1c", "aktau"}}, Output: "\",x09\x41\xb4\x1c\",aktau\n"}, + {Input: [][]string{{"a", "a", ""}}, Output: "a|a|\n", Comma: '|'}, + {Input: [][]string{{",", ",", ""}}, Output: ",|,|\n", Comma: '|'}, + {Input: [][]string{{"foo"}}, Comma: '"', Error: errInvalidDelim}, +} + +func TestWrite(t *testing.T) { + for n, tt := range writeTests { + b := &bytes.Buffer{} + f := NewWriter(b) + f.UseCRLF = tt.UseCRLF + if tt.Comma != 0 { + f.Comma = tt.Comma + } + err := f.WriteAll(tt.Input) + if err != tt.Error { + t.Errorf("Unexpected error:\ngot %v\nwant %v", err, tt.Error) + } + out := b.String() + if out != tt.Output { + t.Errorf("#%d: out=%q want %q", n, out, tt.Output) + } + } +} + +type errorWriter struct{} + +func (e errorWriter) Write(b []byte) (int, error) { + return 0, errors.New("Test") +} + +func TestError(t *testing.T) { + b := &bytes.Buffer{} + f := NewWriter(b) + f.Write([]string{"abc"}) + f.Flush() + err := f.Error() + + if err != nil { + t.Errorf("Unexpected error: %s\n", err) + } + + f = NewWriter(errorWriter{}) + f.Write([]string{"abc"}) + f.Flush() + err = f.Error() + + if err == nil { + t.Error("Error should not be nil") + } +} + +var benchmarkWriteData = [][]string{ + {"abc", "def", "12356", "1234567890987654311234432141542132"}, + {"abc", "def", "12356", "1234567890987654311234432141542132"}, + {"abc", "def", "12356", "1234567890987654311234432141542132"}, +} + +func BenchmarkWrite(b *testing.B) { + for i := 0; i < b.N; i++ { + w := NewWriter(&bytes.Buffer{}) + err := w.WriteAll(benchmarkWriteData) + if err != nil { + b.Fatal(err) + } + w.Flush() + } +} |