Files: b57e8b80419ea2fb7cf7d3b5281d371a2b3976c0 / pack.js
7609 bytesRaw
| 1 | var buffered = require('pull-buffered') |
| 2 | var pull = require('pull-stream') |
| 3 | var toPull = require('stream-to-pull-stream') |
| 4 | var pako = require('pako') |
| 5 | var createHash = require('./util').createHash |
| 6 | var cat = require('pull-cat') |
| 7 | |
| 8 | exports.decode = decodePack |
| 9 | exports.encode = encodePack |
| 10 | |
| 11 | var PACK_VERSION = 2 |
| 12 | |
| 13 | var objectTypes = [ |
| 14 | 'none', 'commit', 'tree', 'blob', |
| 15 | 'tag', 'unused', 'ofs-delta', 'ref-delta' |
| 16 | ] |
| 17 | var objectTypeNums = { |
| 18 | commit: 1, |
| 19 | tree: 2, |
| 20 | blob: 3, |
| 21 | tag: 4 |
| 22 | } |
| 23 | |
| 24 | function error(cb) { |
| 25 | return function (err) { |
| 26 | cb(err || true) |
| 27 | } |
| 28 | } |
| 29 | |
| 30 | function inflateBytes(read) { |
| 31 | var inflate = new pako.Inflate() |
| 32 | var ended, dataOut |
| 33 | |
| 34 | inflate.onData = function (data) { |
| 35 | dataOut = new Buffer(data) |
| 36 | // console.error('inflated data', data.length) |
| 37 | } |
| 38 | |
| 39 | inflate.onEnd = function (status) { |
| 40 | ended = (status === 0) ? true : new Error(inflate.msg) |
| 41 | // console.error('inflated end', status, ended) |
| 42 | } |
| 43 | |
| 44 | return function (abort, cb) { |
| 45 | if (ended) return cb(ended) |
| 46 | read(abort, function next(end, data) { |
| 47 | if (end === true) { |
| 48 | end = null |
| 49 | data = [] |
| 50 | } |
| 51 | if (ended = end) return cb(end) |
| 52 | if (data.length > 1) return cb(new Error('got more than one byte')) |
| 53 | dataOut = null |
| 54 | inflate.push(data, end === true) |
| 55 | if (dataOut) |
| 56 | cb(null, dataOut) |
| 57 | else if (ended) |
| 58 | cb(ended) |
| 59 | else |
| 60 | read(null, next) |
| 61 | }) |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | function deflate(read) { |
| 66 | var def = new pako.Deflate() |
| 67 | var queue = [] |
| 68 | var ended |
| 69 | |
| 70 | def.onData = function (data) { |
| 71 | queue.push([null, new Buffer(data)]) |
| 72 | } |
| 73 | |
| 74 | def.onEnd = function (status) { |
| 75 | queue.push([(status === 0) ? true : new Error(def.msg)]) |
| 76 | } |
| 77 | |
| 78 | return function readOut(abort, cb) { |
| 79 | /* |
| 80 | function _cb(end, data) { |
| 81 | console.error('sending deflated', end, |
| 82 | data && JSON.stringify(data.toString())) |
| 83 | cb(end, data) |
| 84 | } |
| 85 | */ |
| 86 | if (ended) |
| 87 | cb(ended) |
| 88 | else if (queue.length) |
| 89 | cb.apply(this, queue.shift()) |
| 90 | else |
| 91 | read(abort, function next(end, data) { |
| 92 | if (data) |
| 93 | console.error('read into deflat', data.length, JSON.stringify(data)) |
| 94 | if (end === true) def.push([], true) |
| 95 | else if (end) return cb(end) |
| 96 | else def.push(data) |
| 97 | readOut(null, cb) |
| 98 | }) |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | function decodePack(onEnd, read) { |
| 103 | if (read === undefined) |
| 104 | return decodePack.bind(this, onEnd) |
| 105 | |
| 106 | var ended |
| 107 | var numObjects = -1 |
| 108 | var checksum = createHash('sha1') |
| 109 | var b = buffered(read) |
| 110 | // TODO: optimize to pass through buffers to checksum |
| 111 | var readByte = checksum(b.chunks(1)) |
| 112 | var readWord = checksum(b.chunks(4)) |
| 113 | var readChecksum = b.chunks(20) |
| 114 | var expectChecksum = true |
| 115 | var opts = { |
| 116 | verbosity: 2 |
| 117 | } |
| 118 | |
| 119 | function readHeader(cb) { |
| 120 | readWord(null, function (end, header) { |
| 121 | if (ended = end) return cb(end) |
| 122 | if (!header.equals(header, new Buffer('PACK'))) |
| 123 | read(new Error('Invalid packfile header'), error(cb)) |
| 124 | else |
| 125 | readVersion(cb) |
| 126 | }) |
| 127 | } |
| 128 | |
| 129 | function readVersion(cb) { |
| 130 | readWord(null, function (end, word) { |
| 131 | if (ended = end) return cb(end) |
| 132 | var version = word.readUInt32BE() |
| 133 | if (version < 2 || version > 3) |
| 134 | read(new Error('Invalid packfile version ' + version), error(cb)) |
| 135 | else |
| 136 | readNumObjects(cb) |
| 137 | }) |
| 138 | } |
| 139 | |
| 140 | function readNumObjects(cb) { |
| 141 | readWord(null, function (end, word) { |
| 142 | if (ended = end) return cb(end) |
| 143 | numObjects = word.readUInt32BE() |
| 144 | if (opts.verbosity >= 1) |
| 145 | console.error(numObjects + ' objects') |
| 146 | readObject(null, cb) |
| 147 | }) |
| 148 | } |
| 149 | |
| 150 | function readVarInt(cb) { |
| 151 | var type, value, shift |
| 152 | // https://codewords.recurse.com/images/three/varint.svg |
| 153 | readByte(null, function (end, buf) { |
| 154 | if (ended = end) return cb(end) |
| 155 | var firstByte = buf[0] |
| 156 | type = objectTypes[(firstByte >> 4) & 7] |
| 157 | value = firstByte & 15 |
| 158 | console.error('byte1', firstByte, firstByte.toString(2), value, value.toString(2)) |
| 159 | shift = 4 |
| 160 | checkByte(firstByte) |
| 161 | }) |
| 162 | |
| 163 | function checkByte(byte) { |
| 164 | if (byte & 0x80) |
| 165 | readByte(null, gotByte) |
| 166 | else |
| 167 | cb(null, type, value) |
| 168 | } |
| 169 | |
| 170 | function gotByte(end, buf) { |
| 171 | if (ended = end) return cb(end) |
| 172 | var byte = buf[0] |
| 173 | value += (byte & 0x7f) << shift |
| 174 | shift += 7 |
| 175 | console.error('byte', byte, byte.toString(2), value, value.toString(2)) |
| 176 | checkByte(byte) |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | function getObject(cb) { |
| 181 | readVarInt(function (end, type, length) { |
| 182 | if (opts.verbosity >= 2) |
| 183 | console.error('read var int', end, type, length) |
| 184 | numObjects-- |
| 185 | if (end === true && expectChecksum) |
| 186 | onEnd(new Error('Missing checksum')) |
| 187 | if (ended = end) return cb(end) |
| 188 | // TODO: verify that the inflated data is the correct length |
| 189 | cb(null, type, length, inflateBytes(readByte)) |
| 190 | }) |
| 191 | } |
| 192 | |
| 193 | function readTrailer(cb) { |
| 194 | // read the checksum before it updates to include the trailer |
| 195 | var expected = checksum.digest() |
| 196 | readChecksum(null, function (end, value) { |
| 197 | cb(true) |
| 198 | if (end === true && expectChecksum) |
| 199 | onEnd(new Error('Missing checksum')) |
| 200 | if (!value.equals(expected)) { |
| 201 | onEnd(new Error('Checksum mismatch: ' + |
| 202 | expected.hexSlice() + ' != ' + value.hexSlice())) |
| 203 | } else { |
| 204 | if (opts.verbosity >= 2) |
| 205 | console.error('checksum ok', expected.hexSlice()) |
| 206 | onEnd(null) |
| 207 | } |
| 208 | }) |
| 209 | } |
| 210 | |
| 211 | function readObject(abort, cb) { |
| 212 | if (ended) cb(ended) |
| 213 | else if (abort) read(abort) |
| 214 | else if (numObjects < 0) readHeader(cb) |
| 215 | else if (numObjects > 0) getObject(cb) |
| 216 | else if (expectChecksum) readTrailer(cb) |
| 217 | } |
| 218 | |
| 219 | return readObject |
| 220 | } |
| 221 | |
| 222 | function once(read) { |
| 223 | var done |
| 224 | return function (abort, cb) { |
| 225 | if (done) cb(done) |
| 226 | else done = true, read(abort, cb) |
| 227 | } |
| 228 | } |
| 229 | |
| 230 | function encodeVarInt(typeStr, length, cb) { |
| 231 | var type = objectTypeNums[typeStr] |
| 232 | // console.error('TYPE', type, typeStr, 'len', length, typeof cb) |
| 233 | if (!type) |
| 234 | return cb(new Error("Bad object type " + typeStr)) |
| 235 | |
| 236 | var vals = [] |
| 237 | var b = (type << 4) | (length & 15) |
| 238 | for (length >>= 4; length; length >>= 7) { |
| 239 | vals.push(b | 0x80) |
| 240 | b = length & 0x7f |
| 241 | } |
| 242 | vals.push(b) |
| 243 | console.error('sending var int', vals, vals.map(function (n) { |
| 244 | return ('00000000' + Number(n).toString(2)).substr(-8) |
| 245 | })) |
| 246 | cb(null, new Buffer(vals)) |
| 247 | } |
| 248 | |
| 249 | /* |
| 250 | function flow(read) { |
| 251 | return function (abort, cb) { |
| 252 | read(abort, cb, function nextCb(newRead, onEnd) { |
| 253 | read = newRead |
| 254 | return function (end, data) { |
| 255 | cb(end, data) |
| 256 | if (end) onEnd(end === true ? null : end) |
| 257 | } |
| 258 | }) |
| 259 | } |
| 260 | } |
| 261 | */ |
| 262 | |
| 263 | function encodePack(numObjects, readObject) { |
| 264 | // var ended |
| 265 | var header = new Buffer(12) |
| 266 | header.write('PACK') |
| 267 | header.writeUInt32BE(PACK_VERSION, 4) |
| 268 | header.writeUInt32BE(numObjects, 8) |
| 269 | var checksum = createHash('sha1') |
| 270 | var readData |
| 271 | |
| 272 | /* |
| 273 | return pull.through(function (data) { |
| 274 | console.error('> ' + data.length, JSON.stringify(data.toString('ascii'))) |
| 275 | })(cat([ |
| 276 | */ |
| 277 | return cat([ |
| 278 | checksum(cat([ |
| 279 | pull.once(header), |
| 280 | encodeObject |
| 281 | ])), |
| 282 | checksum.readDigest |
| 283 | ]) |
| 284 | // ) |
| 285 | |
| 286 | function encodeObject(abort, cb) { |
| 287 | if (readData) |
| 288 | readData(abort, function (end, data) { |
| 289 | if (end === true) |
| 290 | readObject(abort, nextObject) |
| 291 | else |
| 292 | cb(end, data) |
| 293 | }) |
| 294 | else |
| 295 | readObject(abort, nextObject) |
| 296 | |
| 297 | function nextObject(end, type, length, read) { |
| 298 | // console.error('got obj', end, type, length) |
| 299 | if (end) return cb(end) |
| 300 | readData = deflate(read) |
| 301 | encodeVarInt(type, length, cb) // nextCb(deflate(read), encodeObject)) |
| 302 | } |
| 303 | } |
| 304 | } |
| 305 |
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