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1 | 1 | package gocdx |
2 | 2 |
|
3 | | -import "io" |
| 3 | +import ( |
| 4 | + "bufio" |
| 5 | + "crypto/sha1" |
| 6 | + "encoding/base32" |
| 7 | + "io" |
| 8 | + "strconv" |
| 9 | + "strings" |
| 10 | + "time" |
| 11 | + |
| 12 | + "github.com/internetarchive/gocdx/pkg/surt" |
| 13 | + warc "github.com/internetarchive/gowarc" |
| 14 | +) |
| 15 | + |
| 16 | +type overloadedWARCRecord struct { |
| 17 | + *warc.Record |
| 18 | + |
| 19 | + compByteOffset int64 |
| 20 | + compByteLength int64 |
| 21 | + httpMessage string |
| 22 | + httpHeaders map[string]string |
| 23 | + warcFileName string |
| 24 | +} |
4 | 25 |
|
5 | 26 | // Generate reads a WARC file from the provided reader and returns a slice of Record generated from the given WARC records. |
6 | | -func Generate(warc io.Reader, header string) ([]Record, error) { |
7 | | - // This function is a placeholder for the actual implementation of generating |
8 | | - // a CDX file from a WARC reader. The implementation would typically involve |
9 | | - // reading the WARC records, extracting necessary fields, and formatting them |
10 | | - // according to the CDX specification. |
11 | | - |
12 | | - // For now, we will return an empty slice and nil error. |
13 | | - return []Record{}, nil |
| 27 | +func Generate(warcFile io.ReadCloser, header string) ([]*Record, error) { |
| 28 | + warcReader, err := warc.NewReader(warcFile) |
| 29 | + if err != nil { |
| 30 | + return nil, err |
| 31 | + } |
| 32 | + |
| 33 | + var currentPosition int64 |
| 34 | + var warcFileName string |
| 35 | + var i int |
| 36 | + |
| 37 | + var warcRecords []*overloadedWARCRecord |
| 38 | + for { |
| 39 | + warcRecord, size, err := warcReader.ReadRecord() |
| 40 | + if err != nil { |
| 41 | + return nil, err |
| 42 | + } |
| 43 | + if size == 0 { |
| 44 | + // EOF reached, no more records |
| 45 | + break |
| 46 | + } |
| 47 | + |
| 48 | + if i == 0 && warcRecord.Header.Get("WARC-Filename") != "" { |
| 49 | + warcFileName = warcRecord.Header.Get("WARC-Filename") |
| 50 | + } else if i == 0 { |
| 51 | + // If the first record does not have a WARC-Filename, this is an error that we want to soft-fail |
| 52 | + warcFileName = "unknown.warc" |
| 53 | + } |
| 54 | + |
| 55 | + var httpMessage string |
| 56 | + var httpHeaders map[string]string |
| 57 | + if warcRecord.Header.Get("WARC-Type") == "response" { |
| 58 | + httpMessage, httpHeaders = parseHTTPHeadersFromWARCRecord(warcRecord) |
| 59 | + } |
| 60 | + parsedWARCRecord := &overloadedWARCRecord{ |
| 61 | + Record: warcRecord, |
| 62 | + compByteOffset: currentPosition, |
| 63 | + compByteLength: size, |
| 64 | + httpMessage: httpMessage, |
| 65 | + httpHeaders: httpHeaders, |
| 66 | + warcFileName: warcFileName, |
| 67 | + } |
| 68 | + |
| 69 | + // spew.Dump(parsedWARCRecord) |
| 70 | + |
| 71 | + warcRecords = append(warcRecords, parsedWARCRecord) |
| 72 | + parsedWARCRecord.Record.Content.Close() // Close the content to avoid memory leaks as we are not using it here |
| 73 | + |
| 74 | + currentPosition += size |
| 75 | + } |
| 76 | + |
| 77 | + // spew.Dump(warcRecords) |
| 78 | + |
| 79 | + headerFields := strings.FieldsSeq(header) |
| 80 | + |
| 81 | + records := make([]*Record, 0) |
| 82 | + for _, warcRecord := range warcRecords { |
| 83 | + if warcRecord.Record.Header.Get("WARC-Type") != "response" { |
| 84 | + // Only process records with WARC-Type "response" |
| 85 | + continue |
| 86 | + } |
| 87 | + |
| 88 | + record := &Record{} |
| 89 | + for field := range headerFields { |
| 90 | + switch field { |
| 91 | + case "N": |
| 92 | + record.MassagedURL = surt.Massage(warcRecord.Record.Header.Get("WARC-Target-URI")) |
| 93 | + case "b": |
| 94 | + parsedTime, err := time.Parse(time.RFC3339, warcRecord.Record.Header.Get("WARC-Date")) |
| 95 | + if err != nil { |
| 96 | + parsedTime = time.Time{} |
| 97 | + } |
| 98 | + record.Timestamp = parsedTime |
| 99 | + case "a": |
| 100 | + record.OriginalURL = warcRecord.Record.Header.Get("WARC-Target-URI") |
| 101 | + case "m": |
| 102 | + record.MIMEType = strings.TrimSuffix(warcRecord.Record.Header.Get("Content-Type"), "; msgtype=response") |
| 103 | + case "s": |
| 104 | + record.StatusCode = -1 |
| 105 | + |
| 106 | + splittedHTTPMessage := strings.Split(warcRecord.httpMessage, " ") |
| 107 | + if len(splittedHTTPMessage) >= 2 { |
| 108 | + parsedStatusCode, err := strconv.Atoi(splittedHTTPMessage[1]) |
| 109 | + if err == nil { |
| 110 | + record.StatusCode = parsedStatusCode |
| 111 | + } |
| 112 | + } |
| 113 | + case "k": |
| 114 | + trimmed := strings.TrimPrefix(warcRecord.Record.Header.Get("WARC-Block-Digest"), "sha1:") |
| 115 | + if trimmed != warcRecord.Record.Header.Get("WARC-Block-Digest") { |
| 116 | + record.NewStyleChecksum = trimmed |
| 117 | + } else { |
| 118 | + hasher := sha1.New() |
| 119 | + warcRecord.Record.Content.Seek(0, 0) |
| 120 | + io.Copy(hasher, warcRecord.Record.Content) |
| 121 | + record.NewStyleChecksum = base32.StdEncoding.EncodeToString(hasher.Sum(nil)) |
| 122 | + } |
| 123 | + case "r": |
| 124 | + // TODO : clarify with whoever what to do with this field |
| 125 | + record.Redirect = "-" |
| 126 | + case "M": |
| 127 | + // TODO : let's ignore this field for now |
| 128 | + record.MetaTags = "-" |
| 129 | + case "S": |
| 130 | + record.CompressedRecordSize = warcRecord.compByteLength |
| 131 | + case "V": |
| 132 | + record.CompressedArcOffset = warcRecord.compByteOffset |
| 133 | + case "g": |
| 134 | + record.Filename = warcRecord.warcFileName |
| 135 | + } |
| 136 | + } |
| 137 | + records = append(records, record) |
| 138 | + } |
| 139 | + |
| 140 | + return records, nil |
| 141 | +} |
| 142 | + |
| 143 | +// FormatCDX formats a Record into a CDX string based on the header format. |
| 144 | +func (r *Record) FormatCDX(header string) (string, error) { |
| 145 | + var result strings.Builder |
| 146 | + headerFields := strings.FieldsSeq(header) |
| 147 | + |
| 148 | + for field := range headerFields { |
| 149 | + switch field { |
| 150 | + case "N": |
| 151 | + result.WriteString(r.MassagedURL) |
| 152 | + case "b": |
| 153 | + result.WriteString(r.Timestamp.Format("20060102150405")) |
| 154 | + case "a": |
| 155 | + result.WriteString(r.OriginalURL) |
| 156 | + case "m": |
| 157 | + result.WriteString(r.MIMEType) |
| 158 | + case "s": |
| 159 | + result.WriteString(strconv.Itoa(r.StatusCode)) |
| 160 | + case "k": |
| 161 | + result.WriteString(r.NewStyleChecksum) |
| 162 | + case "r": |
| 163 | + result.WriteString(r.Redirect) |
| 164 | + case "M": |
| 165 | + result.WriteString(r.MetaTags) |
| 166 | + case "S": |
| 167 | + result.WriteString(strconv.FormatInt(r.CompressedRecordSize, 10)) |
| 168 | + case "V": |
| 169 | + result.WriteString(strconv.FormatInt(r.CompressedArcOffset, 10)) |
| 170 | + case "g": |
| 171 | + result.WriteString(r.Filename) |
| 172 | + } |
| 173 | + result.WriteString(" ") |
| 174 | + } |
| 175 | + |
| 176 | + return strings.TrimSpace(result.String()), nil |
| 177 | +} |
| 178 | + |
| 179 | +func parseHTTPHeadersFromWARCRecord(warcRecord *warc.Record) (message string, headers map[string]string) { |
| 180 | + headers = make(map[string]string) |
| 181 | + |
| 182 | + var i int |
| 183 | + scanner := bufio.NewScanner(warcRecord.Content) |
| 184 | + for scanner.Scan() { |
| 185 | + line := scanner.Text() |
| 186 | + if line == "" { |
| 187 | + break |
| 188 | + } |
| 189 | + |
| 190 | + // handle HTTP message |
| 191 | + if i == 0 { |
| 192 | + message = strings.Clone(line) |
| 193 | + i++ |
| 194 | + continue |
| 195 | + } |
| 196 | + |
| 197 | + parts := strings.SplitN(line, ": ", 2) |
| 198 | + if len(parts) == 2 { |
| 199 | + headers[strings.ToLower(parts[0])] = strings.ToLower(parts[1]) |
| 200 | + } |
| 201 | + |
| 202 | + i++ |
| 203 | + } |
| 204 | + |
| 205 | + return |
14 | 206 | } |
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