| 244 | return val; |
| 245 | } |
| 246 | static UInt128 decode128FromByteSource(strings::ByteSource* src) { |
| 247 | UInt128 val = 0; |
| 248 | int32_t shift = 0; |
| 249 | int32_t max_size = kMaxSize128; |
| 250 | folly::StringPiece chunk; |
| 251 | int32_t remaining = 0; |
| 252 | const char* p = nullptr; |
| 253 | for (;;) { |
| 254 | if (remaining == 0) { |
| 255 | CHECK(src->next(&chunk)); |
| 256 | p = chunk.start(); |
| 257 | remaining = chunk.size(); |
| 258 | DCHECK_GT(remaining, 0); |
| 259 | } |
| 260 | --remaining; |
| 261 | if (*p & 0x80) { |
| 262 | CHECK_GT(max_size, 1); // We must have room for the last byte, too |
| 263 | --max_size; |
| 264 | val |= UInt128(*p++ & 0x7f) << shift; |
| 265 | shift += 7; |
| 266 | } else { |
| 267 | val |= UInt128(*p++) << shift; |
| 268 | break; |
| 269 | } |
| 270 | } |
| 271 | if (remaining) { |
| 272 | src->backUp(remaining); |
| 273 | } |
| 274 | return val; |
| 275 | } |
| 276 | }; |
| 277 | |
| 278 | // Zig-zag encoding that maps signed integers with a small absolute value |