update readme

README.md

@@ -5,18 +5,68 @@
 [![Go Report](https://goreportcard.com/badge/github.com/qianbin/directcache)](https://goreportcard.com/report/github.com/qianbin/directcache)
 
 
-A high performance GC-free cache library for Go-lang.
+The high performance GC-free cache library for Golang.
 
 ### Features
 
-- high performance
-- no GC overhead
-- LRU & custom eviction policy
-- zero-copy access
-- small per-entry space overhead
+- Fast set/get, scales well with the number of goroutines
+- High hit rate, benefit from LRU & custom eviction policies
+- GC friendly, almost zero GC overhead
+- Zero-copy access
+
+### Installation
+
+It requires Go 1.12 or newer.
+
+```bash
+go get github.com/qianbin/directcache
+```
+
+### Usage
+
+```go
+// capacity will be set to directcache.MinCapacity
+c := directcache.New(0)
+
+key := []byte("DirectCache")
+val := []byte("is awesome,")
+
+c.Set(key, val)
+got, ok := c.Get(key)
+
+fmt.Println(string(key), string(got), ok)
+// Output: DirectCache is awesome, true
+```
+
+zero-copy access 
+
+```go
+c.AdvGet(
+    key, 
+    func(val []byte){        
+        // consume the value
+    },
+    true, // peek, which means the recently-used flag won't be added to the accessed entry.
+)
+```
+
+custom eviction policy
+```go
+shouldEvict := func(entry directcache.Entry) bool {
+    if entry.RecentlyUsed() {
+        return false
+    }
+    // custom rules...
+    return true
+}
+
+c.SetEvictionPolicy(shouldEvict)
+```
 
 ### Benchmarks
 
+The performance is compared with [FreeCache](https://github.com/coocood/freecache), [FastCache](https://github.com/VictoriaMetrics/fastcache) and [BigCache](https://github.com/allegro/bigcache). The code of benchmarks can be found under [./benches/](./benches/).
+
 ```bash
 $ cd benches
 $ go test -run=^$ -bench ^Benchmark benches -benchtime=5s
@@ -28,18 +78,22 @@ BenchmarkGet/DirectCache-8               37590464      158.7 ns/op    151.22 MB/
 BenchmarkGet/FreeCache-8                 25786171      230.9 ns/op    103.96 MB/s
 BenchmarkGet/FastCache-8                 37254318      159.3 ns/op    150.64 MB/s
 BenchmarkGet/BigCache-8                  37842639      186.1 ns/op    128.97 MB/s
+
 BenchmarkParallelGet/DirectCache-8      161808373      36.99 ns/op    648.87 MB/s
 BenchmarkParallelGet/FreeCache-8        100000000      53.11 ns/op    451.90 MB/s
 BenchmarkParallelGet/FastCache-8        179409560      33.35 ns/op    719.61 MB/s
 BenchmarkParallelGet/BigCache-8         134716734      44.69 ns/op    536.99 MB/s
+
 BenchmarkSet/DirectCache-8               25885528      371.9 ns/op     64.54 MB/s
 BenchmarkSet/FreeCache-8                 26270774      335.2 ns/op     71.60 MB/s
 BenchmarkSet/FastCache-8                 28288302      225.2 ns/op    106.58 MB/s
 BenchmarkSet/BigCache-8                  19396027      462.2 ns/op     51.93 MB/s
+
 BenchmarkParallelSet/DirectCache-8       84369208      85.00 ns/op    282.34 MB/s
 BenchmarkParallelSet/FreeCache-8         73204508      86.74 ns/op    276.68 MB/s
 BenchmarkParallelSet/FastCache-8         82061668      86.49 ns/op    277.50 MB/s
 BenchmarkParallelSet/BigCache-8          71246137      96.85 ns/op    247.81 MB/s
+
 BenchmarkParallelSetGet/DirectCache-8    32410581      215.7 ns/op    111.26 MB/s
 BenchmarkParallelSetGet/FreeCache-8      23206942      293.7 ns/op     81.71 MB/s
 BenchmarkParallelSetGet/FastCache-8      32624253      179.3 ns/op    133.87 MB/s
@@ -71,55 +125,6 @@ PASS
 ok  	benches	3.439s
 ```
 
-### Installation
-
-It requires Go 1.12 or newer.
-
-```bash
-go get github.com/qianbin/directcache
-```
-
-### Usage
-
-```go
-// capacity will be set to directcache.MinCapacity
-c := directcache.New(0)
-
-key := []byte("DirectCache")
-val := []byte("is awesome,")
-
-c.Set(key, val)
-got, ok := c.Get(key)
-
-fmt.Println(string(key), string(got), ok)
-// Output: DirectCache is awesome, true
-```
-
-zero-copy access 
-
-```go
-c.AdvGet(
-    key, 
-    func(val []byte){        
-        // consume the value
-    },
-    true, // peek, which means the recently-used flag won't be added to the accessed entry.
-)
-```
-
-custom eviction policy
-```go
-shouldEvict := func(entry directcache.Entry) bool {
-    if entry.RecentlyUsed() {
-        return false
-    }
-    // custom rules...
-    return true
-}
-
-c.SetEvictionPolicy(shouldEvict)
-```
-
 ## License
 
 The MIT License