实现基础web服务器

vendor/github.com/bytedance/sonic/internal/decoder/decoder.go

@@ -0,0 +1,255 @@
+/*
+ * 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 decoder
+
+import (
+    `unsafe`
+    `encoding/json`
+    `reflect`
+    `runtime`
+
+    `github.com/bytedance/sonic/internal/native`
+    `github.com/bytedance/sonic/internal/native/types`
+    `github.com/bytedance/sonic/internal/rt`
+    `github.com/bytedance/sonic/option`
+    `github.com/bytedance/sonic/utf8`
+)
+
+const (
+    _F_use_int64 = iota
+    _F_use_number
+    _F_disable_urc
+    _F_disable_unknown
+    _F_copy_string
+    _F_validate_string
+
+    _F_allow_control = 31
+)
+
+type Options uint64
+
+const (
+    OptionUseInt64         Options = 1 << _F_use_int64
+    OptionUseNumber        Options = 1 << _F_use_number
+    OptionUseUnicodeErrors Options = 1 << _F_disable_urc
+    OptionDisableUnknown   Options = 1 << _F_disable_unknown
+    OptionCopyString       Options = 1 << _F_copy_string
+    OptionValidateString   Options = 1 << _F_validate_string
+)
+
+func (self *Decoder) SetOptions(opts Options) {
+    if (opts & OptionUseNumber != 0) && (opts & OptionUseInt64 != 0) {
+        panic("can't set OptionUseInt64 and OptionUseNumber both!")
+    }
+    self.f = uint64(opts)
+}
+
+
+// Decoder is the decoder context object
+type Decoder struct {
+    i int
+    f uint64
+    s string
+}
+
+// NewDecoder creates a new decoder instance.
+func NewDecoder(s string) *Decoder {
+    return &Decoder{s: s}
+}
+
+// Pos returns the current decoding position.
+func (self *Decoder) Pos() int {
+    return self.i
+}
+
+func (self *Decoder) Reset(s string) {
+    self.s = s
+    self.i = 0
+    // self.f = 0
+}
+
+func (self *Decoder) CheckTrailings() error {
+    pos := self.i
+    buf := self.s
+    /* skip all the trailing spaces */
+    if pos != len(buf) {
+        for pos < len(buf) && (types.SPACE_MASK & (1 << buf[pos])) != 0 {
+            pos++
+        }
+    }
+
+    /* then it must be at EOF */
+    if pos == len(buf) {
+        return nil
+    }
+
+    /* junk after JSON value */
+    return SyntaxError {
+        Src  : buf,
+        Pos  : pos,
+        Code : types.ERR_INVALID_CHAR,
+    }
+}
+
+
+// Decode parses the JSON-encoded data from current position and stores the result
+// in the value pointed to by val.
+func (self *Decoder) Decode(val interface{}) error {
+    /* validate json if needed */
+    if (self.f & (1 << _F_validate_string)) != 0  && !utf8.ValidateString(self.s){
+        dbuf := utf8.CorrectWith(nil, rt.Str2Mem(self.s), "\ufffd")
+        self.s = rt.Mem2Str(dbuf)
+    }
+
+    vv := rt.UnpackEface(val)
+    vp := vv.Value
+
+    /* check for nil type */
+    if vv.Type == nil {
+        return &json.InvalidUnmarshalError{}
+    }
+
+    /* must be a non-nil pointer */
+    if vp == nil || vv.Type.Kind() != reflect.Ptr {
+        return &json.InvalidUnmarshalError{Type: vv.Type.Pack()}
+    }
+
+    etp := rt.PtrElem(vv.Type)
+
+    /* check the defined pointer type for issue 379 */
+    if vv.Type.IsNamed() {
+        newp := vp
+        etp  = vv.Type
+        vp   = unsafe.Pointer(&newp)
+    }
+
+    /* create a new stack, and call the decoder */
+    sb := newStack()
+    nb, err := decodeTypedPointer(self.s, self.i, etp, vp, sb, self.f)
+    /* return the stack back */
+    self.i = nb
+    freeStack(sb)
+
+    /* avoid GC ahead */
+    runtime.KeepAlive(vv)
+    return err
+}
+
+// UseInt64 indicates the Decoder to unmarshal an integer into an interface{} as an
+// int64 instead of as a float64.
+func (self *Decoder) UseInt64() {
+    self.f  |= 1 << _F_use_int64
+    self.f &^= 1 << _F_use_number
+}
+
+// UseNumber indicates the Decoder to unmarshal a number into an interface{} as a
+// json.Number instead of as a float64.
+func (self *Decoder) UseNumber() {
+    self.f &^= 1 << _F_use_int64
+    self.f  |= 1 << _F_use_number
+}
+
+// UseUnicodeErrors indicates the Decoder to return an error when encounter invalid
+// UTF-8 escape sequences.
+func (self *Decoder) UseUnicodeErrors() {
+    self.f |= 1 << _F_disable_urc
+}
+
+// DisallowUnknownFields indicates the Decoder to return an error when the destination
+// is a struct and the input contains object keys which do not match any
+// non-ignored, exported fields in the destination.
+func (self *Decoder) DisallowUnknownFields() {
+    self.f |= 1 << _F_disable_unknown
+}
+
+// CopyString indicates the Decoder to decode string values by copying instead of referring.
+func (self *Decoder) CopyString() {
+    self.f |= 1 << _F_copy_string
+}
+
+// ValidateString causes the Decoder to validate string values when decoding string value 
+// in JSON. Validation is that, returning error when unescaped control chars(0x00-0x1f) or
+// invalid UTF-8 chars in the string value of JSON.
+func (self *Decoder) ValidateString() {
+    self.f |= 1 << _F_validate_string
+}
+
+// Pretouch compiles vt ahead-of-time to avoid JIT compilation on-the-fly, in
+// order to reduce the first-hit latency.
+//
+// Opts are the compile options, for example, "option.WithCompileRecursiveDepth" is
+// a compile option to set the depth of recursive compile for the nested struct type.
+func Pretouch(vt reflect.Type, opts ...option.CompileOption) error {
+    cfg := option.DefaultCompileOptions()
+    for _, opt := range opts {
+        opt(&cfg)
+    }
+    return pretouchRec(map[reflect.Type]bool{vt:true}, cfg)
+}
+
+func pretouchType(_vt reflect.Type, opts option.CompileOptions) (map[reflect.Type]bool, error) {
+    /* compile function */
+    compiler := newCompiler().apply(opts)
+    decoder := func(vt *rt.GoType, _ ...interface{}) (interface{}, error) {
+        if pp, err := compiler.compile(_vt); err != nil {
+            return nil, err
+        } else {
+            as := newAssembler(pp)
+            as.name = _vt.String()
+            return as.Load(), nil
+        }
+    }
+
+    /* find or compile */
+    vt := rt.UnpackType(_vt)
+    if val := programCache.Get(vt); val != nil {
+        return nil, nil
+    } else if _, err := programCache.Compute(vt, decoder); err == nil {
+        return compiler.rec, nil
+    } else {
+        return nil, err
+    }
+}
+
+func pretouchRec(vtm map[reflect.Type]bool, opts option.CompileOptions) error {
+    if opts.RecursiveDepth < 0 || len(vtm) == 0 {
+        return nil
+    }
+    next := make(map[reflect.Type]bool)
+    for vt := range(vtm) {
+        sub, err := pretouchType(vt, opts)
+        if err != nil {
+            return err
+        }
+        for svt := range(sub) {
+            next[svt] = true
+        }
+    }
+    opts.RecursiveDepth -= 1
+    return pretouchRec(next, opts)
+}
+
+// Skip skips only one json value, and returns first non-blank character position and its ending position if it is valid.
+// Otherwise, returns negative error code using start and invalid character position using end
+func Skip(data []byte) (start int, end int) {
+    s := rt.Mem2Str(data)
+    p := 0
+    m := types.NewStateMachine()
+    ret := native.SkipOne(&s, &p, m, uint64(0))
+    types.FreeStateMachine(m) 
+    return ret, p
+}