FOLLY: FBString
folly/FBString.h
fbstring is a replacement for std::string. The main benefit of fbstring is significantly increased performance on virtually all important primitives. This is achieved by using a three-tiered
storage strategy and by cooperating with the memory allocator. fbstring is
designed to detect use of jemalloc. To achieve significant improvements in
speed and memory usage fbstring cooperates with it.
Storage strategies
- Small strings (<= 23 chars) are stored in-situ without memory allocation.
- Medium strings (24 - 255 chars) are stored in malloc-allocated memory and copied
eagerly. - Large strings (> 255 chars) are stored in malloc-allocated memory and copied
lazily.
Implementation highlights
- 100% compatible with std::string.
- Thread-safe reference counted copy-on-write for strings "large" strings
(> 255 chars). - Uses malloc instead of allocators.
- Jemalloc-friendly. fbstring automatically detects if application uses jemalloc and if so, significantly improves allocation strategy by using non-standard jemalloc extensions.
- find() is implemented using simplified Boyer-Moore algorithm. Casual tests indicate
a 30x speed improvement over string::find() for successful
searches and a 1.5x speed improvement for failed searches.
More Articles of Himanshu Singh:
| Name | Views | Likes |
|---|---|---|
| FOLLY: Benefits | 104 | 1 |
| FOLLY: synchronization/Rcu.h | 224 | 1 |
| FOLLY: Synchronized.h (3) | 155 | 1 |
| FOLLY: Synchronized.h (2) | 179 | 1 |
| FOLLY: Synchronized.h (1) | 214 | 1 |
| FOLLY: dynamic.h | 284 | 1 |
| FOLLY: Benchmark.h | 126 | 1 |
| FOLLY: stats/Histogram.h | 165 | 1 |
| FOLLY: PackedSyncPtr.h | 107 | 1 |
| FOLLY: ProducerConsumerQueue.h | 179 | 1 |
| FOLLY: SmallLocks.h | 93 | 1 |
| FOLLY: ThreadCachedInt.h (2) | 93 | 1 |
| FOLLY: ThreadCachedInt.h (1) | 98 | 1 |
| FOLLY: ThreadLocal.h | 134 | 1 |
| FOLLY: small_vector.h | 241 | 1 |
| FOLLY: GroupVarint.h | 119 | 1 |
| FOLLY: Function.h | 181 | 1 |
| FOLLY: Format.h | 164 | 1 |
| FOLLY: FBVector | 176 | 1 |
| FOLLY: FBString | 107 | 1 |
| FOLLY: Thread pools & Executors | 106 | 1 |
| FOLLY: DynamicConverter | 88 | 1 |
| FOLLY: AtomicHashMap | 142 | 1 |
| FOLLY: Components | 114 | 1 |
| FOLLY: Overview | 164 | 1 |
Comments