实现基础web服务器

vendor/github.com/bytedance/sonic/internal/encoder/mapiter.go

@@ -0,0 +1,199 @@
+/*
+ * Copyright 2021 ByteDance Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package encoder
+
+import (
+	"encoding"
+	"reflect"
+	"sync"
+	"unsafe"
+
+	"github.com/bytedance/sonic/internal/native"
+	"github.com/bytedance/sonic/internal/rt"
+)
+
+type _MapPair struct {
+    k string  // when the map key is integer, k is pointed to m
+    v unsafe.Pointer
+    m [32]byte
+}
+
+type _MapIterator struct {
+    it rt.GoMapIterator     // must be the first field
+    kv rt.GoSlice           // slice of _MapPair
+    ki int
+}
+
+var (
+    iteratorPool = sync.Pool{}
+    iteratorPair = rt.UnpackType(reflect.TypeOf(_MapPair{}))
+)
+
+func init() {
+    if unsafe.Offsetof(_MapIterator{}.it) != 0 {
+        panic("_MapIterator.it is not the first field")
+    }
+}
+
+
+func newIterator() *_MapIterator {
+    if v := iteratorPool.Get(); v == nil {
+        return new(_MapIterator)
+    } else {
+        return resetIterator(v.(*_MapIterator))
+    }
+}
+
+func resetIterator(p *_MapIterator) *_MapIterator {
+    p.ki = 0
+    p.it = rt.GoMapIterator{}
+    p.kv.Len = 0
+    return p
+}
+
+func (self *_MapIterator) at(i int) *_MapPair {
+    return (*_MapPair)(unsafe.Pointer(uintptr(self.kv.Ptr) + uintptr(i) * unsafe.Sizeof(_MapPair{})))
+}
+
+func (self *_MapIterator) add() (p *_MapPair) {
+    p = self.at(self.kv.Len)
+    self.kv.Len++
+    return
+}
+
+func (self *_MapIterator) data() (p []_MapPair) {
+    *(*rt.GoSlice)(unsafe.Pointer(&p)) = self.kv
+    return
+}
+
+func (self *_MapIterator) append(t *rt.GoType, k unsafe.Pointer, v unsafe.Pointer) (err error) {
+    p := self.add()
+    p.v = v
+
+    /* check for strings */
+    if tk := t.Kind(); tk != reflect.String {
+        return self.appendGeneric(p, t, tk, k)
+    }
+
+    /* fast path for strings */
+    p.k = *(*string)(k)
+    return nil
+}
+
+func (self *_MapIterator) appendGeneric(p *_MapPair, t *rt.GoType, v reflect.Kind, k unsafe.Pointer) error {
+    switch v {
+        case reflect.Int       : p.k = rt.Mem2Str(p.m[:native.I64toa(&p.m[0], int64(*(*int)(k)))])      ; return nil
+        case reflect.Int8      : p.k = rt.Mem2Str(p.m[:native.I64toa(&p.m[0], int64(*(*int8)(k)))])     ; return nil
+        case reflect.Int16     : p.k = rt.Mem2Str(p.m[:native.I64toa(&p.m[0], int64(*(*int16)(k)))])    ; return nil
+        case reflect.Int32     : p.k = rt.Mem2Str(p.m[:native.I64toa(&p.m[0], int64(*(*int32)(k)))])    ; return nil
+        case reflect.Int64     : p.k = rt.Mem2Str(p.m[:native.I64toa(&p.m[0], *(*int64)(k))])           ; return nil
+        case reflect.Uint      : p.k = rt.Mem2Str(p.m[:native.U64toa(&p.m[0], uint64(*(*uint)(k)))])    ; return nil
+        case reflect.Uint8     : p.k = rt.Mem2Str(p.m[:native.U64toa(&p.m[0], uint64(*(*uint8)(k)))])   ; return nil
+        case reflect.Uint16    : p.k = rt.Mem2Str(p.m[:native.U64toa(&p.m[0], uint64(*(*uint16)(k)))])  ; return nil
+        case reflect.Uint32    : p.k = rt.Mem2Str(p.m[:native.U64toa(&p.m[0], uint64(*(*uint32)(k)))])  ; return nil
+        case reflect.Uint64    : p.k = rt.Mem2Str(p.m[:native.U64toa(&p.m[0], *(*uint64)(k))])          ; return nil
+        case reflect.Uintptr   : p.k = rt.Mem2Str(p.m[:native.U64toa(&p.m[0], uint64(*(*uintptr)(k)))]) ; return nil
+        case reflect.Interface : return self.appendInterface(p, t, k)
+        case reflect.Struct, reflect.Ptr : return self.appendConcrete(p, t, k)
+        default                : panic("unexpected map key type")
+    }
+}
+
+func (self *_MapIterator) appendConcrete(p *_MapPair, t *rt.GoType, k unsafe.Pointer) (err error) {
+    // compiler has already checked that the type implements the encoding.MarshalText interface
+    if !t.Indirect() {
+        k = *(*unsafe.Pointer)(k)
+    }
+    eface := rt.GoEface{Value: k, Type: t}.Pack()
+    out, err := eface.(encoding.TextMarshaler).MarshalText()
+    if err != nil {
+        return err
+    }
+    p.k = rt.Mem2Str(out)
+    return
+}
+
+func (self *_MapIterator) appendInterface(p *_MapPair, t *rt.GoType, k unsafe.Pointer) (err error) {
+    if len(rt.IfaceType(t).Methods) == 0 {
+        panic("unexpected map key type")
+    } else if p.k, err = asText(k); err == nil {
+        return nil
+    } else {
+        return
+    }
+}
+
+func iteratorStop(p *_MapIterator) {
+    iteratorPool.Put(p)
+}
+
+func iteratorNext(p *_MapIterator) {
+    i := p.ki
+    t := &p.it
+
+    /* check for unordered iteration */
+    if i < 0 {
+        mapiternext(t)
+        return
+    }
+
+    /* check for end of iteration */
+    if p.ki >= p.kv.Len {
+        t.K = nil
+        t.V = nil
+        return
+    }
+
+    /* update the key-value pair, and increase the pointer */
+    t.K = unsafe.Pointer(&p.at(p.ki).k)
+    t.V = p.at(p.ki).v
+    p.ki++
+}
+
+func iteratorStart(t *rt.GoMapType, m *rt.GoMap, fv uint64) (*_MapIterator, error) {
+    it := newIterator()
+    mapiterinit(t, m, &it.it)
+
+    /* check for key-sorting, empty map don't need sorting */
+    if m.Count == 0 || (fv & uint64(SortMapKeys)) == 0 {
+        it.ki = -1
+        return it, nil
+    }
+
+    /* pre-allocate space if needed */
+    if m.Count > it.kv.Cap {
+        it.kv = growslice(iteratorPair, it.kv, m.Count)
+    }
+
+    /* dump all the key-value pairs */
+    for ; it.it.K != nil; mapiternext(&it.it) {
+        if err := it.append(t.Key, it.it.K, it.it.V); err != nil {
+            iteratorStop(it)
+            return nil, err
+        }
+    }
+
+    /* sort the keys, map with only 1 item don't need sorting */
+    if it.ki = 1; m.Count > 1 {
+        radixQsort(it.data(), 0, maxDepth(it.kv.Len))
+    }
+
+    /* load the first pair into iterator */
+    it.it.V = it.at(0).v
+    it.it.K = unsafe.Pointer(&it.at(0).k)
+    return it, nil
+}