diff --git a/gjson.go b/gjson.go index 6b873bd..9ffd77d 100644 --- a/gjson.go +++ b/gjson.go @@ -13,7 +13,6 @@ import ( "time" "unicode/utf16" "unicode/utf8" - "unsafe" "github.com/tidwall/match" ) @@ -1385,64 +1384,14 @@ func Get(json, path string) Result { } } } - if len(c.value.Raw) > 0 && !c.calcd { - jhdr := *(*reflect.StringHeader)(unsafe.Pointer(&json)) - rhdr := *(*reflect.StringHeader)(unsafe.Pointer(&(c.value.Raw))) - c.value.Index = int(rhdr.Data - jhdr.Data) - if c.value.Index < 0 || c.value.Index >= len(json) { - c.value.Index = 0 - } - } + fillIndex(json, c) return c.value } -func fromBytesGet(result Result) Result { - // safely get the string headers - rawhi := *(*reflect.StringHeader)(unsafe.Pointer(&result.Raw)) - strhi := *(*reflect.StringHeader)(unsafe.Pointer(&result.Str)) - // create byte slice headers - rawh := reflect.SliceHeader{Data: rawhi.Data, Len: rawhi.Len} - strh := reflect.SliceHeader{Data: strhi.Data, Len: strhi.Len} - if strh.Data == 0 { - // str is nil - if rawh.Data == 0 { - // raw is nil - result.Raw = "" - } else { - // raw has data, safely copy the slice header to a string - result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh))) - } - result.Str = "" - } else if rawh.Data == 0 { - // raw is nil - result.Raw = "" - // str has data, safely copy the slice header to a string - result.Str = string(*(*[]byte)(unsafe.Pointer(&strh))) - } else if strh.Data >= rawh.Data && - int(strh.Data)+strh.Len <= int(rawh.Data)+rawh.Len { - // Str is a substring of Raw. - start := int(strh.Data - rawh.Data) - // safely copy the raw slice header - result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh))) - // substring the raw - result.Str = result.Raw[start : start+strh.Len] - } else { - // safely copy both the raw and str slice headers to strings - result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh))) - result.Str = string(*(*[]byte)(unsafe.Pointer(&strh))) - } - return result -} // GetBytes searches json for the specified path. // If working with bytes, this method preferred over Get(string(data), path) func GetBytes(json []byte, path string) Result { - var result Result - if json != nil { - // unsafe cast to string - result = Get(*(*string)(unsafe.Pointer(&json)), path) - result = fromBytesGet(result) - } - return result + return getBytes(json, path) } // runeit returns the rune from the the \uXXXX diff --git a/gjson_gae.go b/gjson_gae.go new file mode 100644 index 0000000..cbe2ab4 --- /dev/null +++ b/gjson_gae.go @@ -0,0 +1,10 @@ +//+build appengine + +package gjson + +func getBytes(json []byte, path string) Result { + return Get(string(json), path) +} +func fillIndex(json string, c *parseContext) { + // noop. Use zero for the Index value. +} diff --git a/gjson_ngae.go b/gjson_ngae.go new file mode 100644 index 0000000..ff313a7 --- /dev/null +++ b/gjson_ngae.go @@ -0,0 +1,73 @@ +//+build !appengine + +package gjson + +import ( + "reflect" + "unsafe" +) + +// getBytes casts the input json bytes to a string and safely returns the +// results as uniquely allocated data. This operation is intended to minimize +// copies and allocations for the large json string->[]byte. +func getBytes(json []byte, path string) Result { + var result Result + if json != nil { + // unsafe cast to string + result = Get(*(*string)(unsafe.Pointer(&json)), path) + result = fromBytesGet(result) + } + return result +} + +func fromBytesGet(result Result) Result { + // safely get the string headers + rawhi := *(*reflect.StringHeader)(unsafe.Pointer(&result.Raw)) + strhi := *(*reflect.StringHeader)(unsafe.Pointer(&result.Str)) + // create byte slice headers + rawh := reflect.SliceHeader{Data: rawhi.Data, Len: rawhi.Len} + strh := reflect.SliceHeader{Data: strhi.Data, Len: strhi.Len} + if strh.Data == 0 { + // str is nil + if rawh.Data == 0 { + // raw is nil + result.Raw = "" + } else { + // raw has data, safely copy the slice header to a string + result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh))) + } + result.Str = "" + } else if rawh.Data == 0 { + // raw is nil + result.Raw = "" + // str has data, safely copy the slice header to a string + result.Str = string(*(*[]byte)(unsafe.Pointer(&strh))) + } else if strh.Data >= rawh.Data && + int(strh.Data)+strh.Len <= int(rawh.Data)+rawh.Len { + // Str is a substring of Raw. + start := int(strh.Data - rawh.Data) + // safely copy the raw slice header + result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh))) + // substring the raw + result.Str = result.Raw[start : start+strh.Len] + } else { + // safely copy both the raw and str slice headers to strings + result.Raw = string(*(*[]byte)(unsafe.Pointer(&rawh))) + result.Str = string(*(*[]byte)(unsafe.Pointer(&strh))) + } + return result +} + +// fillIndex finds the position of Raw data and assigns it to the Index field +// of the resulting value. If the position cannot be found then Index zero is +// used instead. +func fillIndex(json string, c *parseContext) { + if len(c.value.Raw) > 0 && !c.calcd { + jhdr := *(*reflect.StringHeader)(unsafe.Pointer(&json)) + rhdr := *(*reflect.StringHeader)(unsafe.Pointer(&(c.value.Raw))) + c.value.Index = int(rhdr.Data - jhdr.Data) + if c.value.Index < 0 || c.value.Index >= len(json) { + c.value.Index = 0 + } + } +}