intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 289 insertions, 0 deletions

diff --git a/library/cpp/json/writer/json.h b/library/cpp/json/writer/json.h
new file mode 100644
index 0000000000..0aae2531b9
--- /dev/null
+++ b/library/cpp/json/writer/json.h
@@ -0,0 +1,289 @@
+#pragma once
+
+#include <util/generic/noncopyable.h>
+#include <util/generic/ptr.h>
+#include <util/generic/string.h>
+#include <util/generic/vector.h>
+#include <util/generic/yexception.h>
+#include <util/stream/str.h>
+#include <util/string/cast.h>
+
+namespace NJson {
+    class TJsonValue;
+}
+
+namespace NJsonWriter {
+    enum EJsonEntity : ui8 {
+        JE_OUTER_SPACE = 1,
+        JE_LIST,
+        JE_OBJECT,
+        JE_PAIR,
+    };
+
+    enum EHtmlEscapeMode {
+        HEM_ESCAPE_HTML = 1,  // Use HTML escaping: &lt; &gt; &amp; \/
+        HEM_DONT_ESCAPE_HTML, // Use JSON escaping: \u003C \u003E \u0026 \/
+        HEM_RELAXED,          // Use JSON escaping: \u003C \u003E \u0026 /
+        HEM_UNSAFE,           // Turn escaping off: < > & /
+    };
+
+    class TError: public yexception {};
+
+    class TValueContext;
+    class TPairContext;
+    class TAfterColonContext;
+
+    struct TBufState {
+        bool NeedComma;
+        bool NeedNewline;
+        TVector<EJsonEntity> Stack;
+    };
+
+    class TBuf : TNonCopyable {
+    public:
+        TBuf(EHtmlEscapeMode mode = HEM_DONT_ESCAPE_HTML, IOutputStream* stream = nullptr);
+
+        TValueContext WriteString(const TStringBuf& s, EHtmlEscapeMode hem);
+        TValueContext WriteString(const TStringBuf& s);
+        TValueContext WriteInt(int i);
+        TValueContext WriteLongLong(long long i);
+        TValueContext WriteULongLong(unsigned long long i);
+        TValueContext WriteFloat(float f, EFloatToStringMode mode = PREC_NDIGITS, int ndigits = 6);
+        TValueContext WriteDouble(double f, EFloatToStringMode mode = PREC_NDIGITS, int ndigits = 10);
+        TValueContext WriteBool(bool b);
+        TValueContext WriteNull();
+        TValueContext WriteJsonValue(const NJson::TJsonValue* value, bool sortKeys = false, EFloatToStringMode mode = PREC_NDIGITS, int ndigits = 10);
+
+        TValueContext BeginList();
+        TBuf& EndList();
+
+        TPairContext BeginObject();
+        TAfterColonContext WriteKey(const TStringBuf& key, EHtmlEscapeMode hem);
+        TAfterColonContext WriteKey(const TStringBuf& key);
+        TAfterColonContext UnsafeWriteKey(const TStringBuf& key);
+        bool KeyExpected() const {
+            return Stack.back() == JE_OBJECT;
+        }
+
+        //! deprecated, do not use in new code
+        TAfterColonContext CompatWriteKeyWithoutQuotes(const TStringBuf& key);
+
+        TBuf& EndObject();
+
+        /*** Indent the resulting JSON with spaces.
+           * By default (spaces==0) no formatting is done.                */
+        TBuf& SetIndentSpaces(int spaces) {
+            IndentSpaces = spaces;
+            return *this;
+        }
+
+        /*** NaN and Inf are not valid json values,
+           * so if WriteNanAsString is set, writer would write string
+           * intead of throwing exception (default case)                  */
+        TBuf& SetWriteNanAsString(bool writeNanAsString = true) {
+            WriteNanAsString = writeNanAsString;
+            return *this;
+        }
+
+        /*** Return the string formed in the internal TStringStream.
+           * You may only call it if the `stream' parameter was NULL
+           * at construction time.                                        */
+        const TString& Str() const;
+
+        /*** Dump and forget the string constructed so far.
+           * You may only call it if the `stream' parameter was NULL
+           * at construction time.                                        */
+        void FlushTo(IOutputStream* stream);
+
+        /*** Write a literal string that represents a JSON value
+           * (string, number, object, array, bool, or null).
+           *
+           * Example:
+           * j.UnsafeWriteValue("[1, 2, 3, \"o'clock\", 4, \"o'clock rock\"]");
+           *
+           * As in all of the Unsafe* functions, no escaping is done.     */
+        void UnsafeWriteValue(const TStringBuf& s);
+        void UnsafeWriteValue(const char* s, size_t len);
+
+        /*** When in the context of an object, write a literal string
+           * that represents a key:value pair (or several pairs).
+           *
+           * Example:
+           * j.BeginObject();
+           * j.UnsafeWritePair("\"adam\": \"male\", \"eve\": \"female\"");
+           * j.EndObject();
+           *
+           * As in all of the Unsafe* functions, no escaping is done.     */
+        TPairContext UnsafeWritePair(const TStringBuf& s);
+
+        /*** Copy the supplied string directly into the output stream.    */
+        void UnsafeWriteRawBytes(const TStringBuf& s);
+        void UnsafeWriteRawBytes(const char* c, size_t len);
+
+        TBufState State() const;
+        void Reset(const TBufState& from);
+        void Reset(TBufState&& from);
+
+    private:
+        void BeginValue();
+        void EndValue();
+        void BeginKey();
+        void RawWriteChar(char c);
+        bool EscapedWriteChar(const char* b, const char* c, EHtmlEscapeMode hem);
+        void WriteBareString(const TStringBuf s, EHtmlEscapeMode hem);
+        void WriteComma();
+        void PrintIndentation(bool closing);
+        void PrintWhitespaces(size_t count, bool prependWithNewLine);
+        void WriteHexEscape(unsigned char c);
+
+        void StackPush(EJsonEntity e);
+        void StackPop();
+        void CheckAndPop(EJsonEntity e);
+        EJsonEntity StackTop() const;
+
+        template <class TFloat>
+        TValueContext WriteFloatImpl(TFloat f, EFloatToStringMode mode, int ndigits);
+
+    private:
+        IOutputStream* Stream;
+        THolder<TStringStream> StringStream;
+        typedef TVector<const TString*> TKeys;
+        TKeys Keys;
+
+        TVector<EJsonEntity> Stack;
+        bool NeedComma;
+        bool NeedNewline;
+        const EHtmlEscapeMode EscapeMode;
+        int IndentSpaces;
+        bool WriteNanAsString;
+    };
+
+    // Please don't try to instantiate the classes declared below this point.
+
+    template <typename TOutContext>
+    class TValueWriter {
+    public:
+        TOutContext WriteNull();
+        TOutContext WriteString(const TStringBuf&);
+        TOutContext WriteString(const TStringBuf& s, EHtmlEscapeMode hem);
+        TOutContext WriteInt(int);
+        TOutContext WriteLongLong(long long);
+        TOutContext WriteULongLong(unsigned long long);
+        TOutContext WriteBool(bool);
+        TOutContext WriteFloat(float);
+        TOutContext WriteFloat(float, EFloatToStringMode, int ndigits);
+        TOutContext WriteDouble(double);
+        TOutContext WriteDouble(double, EFloatToStringMode, int ndigits);
+        TOutContext WriteJsonValue(const NJson::TJsonValue* value, bool sortKeys = false);
+        TOutContext UnsafeWriteValue(const TStringBuf&);
+
+        TValueContext BeginList();
+        TPairContext BeginObject();
+
+    protected:
+        TValueWriter(TBuf& buf)
+            : Buf(buf)
+        {
+        }
+        friend class TBuf;
+
+    protected:
+        TBuf& Buf;
+    };
+
+    class TValueContext: public TValueWriter<TValueContext> {
+    public:
+        TBuf& EndList() {
+            return Buf.EndList();
+        }
+        TString Str() const {
+            return Buf.Str();
+        }
+
+    private:
+        TValueContext(TBuf& buf)
+            : TValueWriter<TValueContext>(buf)
+        {
+        }
+        friend class TBuf;
+        friend class TValueWriter<TValueContext>;
+    };
+
+    class TAfterColonContext: public TValueWriter<TPairContext> {
+    private:
+        TAfterColonContext(TBuf& iBuf)
+            : TValueWriter<TPairContext>(iBuf)
+        {
+        }
+        friend class TBuf;
+        friend class TPairContext;
+    };
+
+    class TPairContext {
+    public:
+        TAfterColonContext WriteKey(const TStringBuf& s, EHtmlEscapeMode hem) {
+            return Buf.WriteKey(s, hem);
+        }
+        TAfterColonContext WriteKey(const TStringBuf& s) {
+            return Buf.WriteKey(s);
+        }
+        TAfterColonContext UnsafeWriteKey(const TStringBuf& s) {
+            return Buf.UnsafeWriteKey(s);
+        }
+        TAfterColonContext CompatWriteKeyWithoutQuotes(const TStringBuf& s) {
+            return Buf.CompatWriteKeyWithoutQuotes(s);
+        }
+        TPairContext UnsafeWritePair(const TStringBuf& s) {
+            return Buf.UnsafeWritePair(s);
+        }
+        TBuf& EndObject() {
+            return Buf.EndObject();
+        }
+
+    private:
+        TPairContext(TBuf& buf)
+            : Buf(buf)
+        {
+        }
+
+        friend class TBuf;
+        friend class TValueWriter<TPairContext>;
+
+    private:
+        TBuf& Buf;
+    };
+
+#define JSON_VALUE_WRITER_WRAP(function, params, args)       \
+    template <typename TOutContext>                          \
+    TOutContext TValueWriter<TOutContext>::function params { \
+        Buf.function args;                                   \
+        return TOutContext(Buf);                             \
+    }
+
+    JSON_VALUE_WRITER_WRAP(WriteNull, (), ())
+    JSON_VALUE_WRITER_WRAP(WriteString, (const TStringBuf& arg), (arg))
+    JSON_VALUE_WRITER_WRAP(WriteString, (const TStringBuf& s, EHtmlEscapeMode hem), (s, hem))
+    JSON_VALUE_WRITER_WRAP(WriteInt, (int arg), (arg))
+    JSON_VALUE_WRITER_WRAP(WriteLongLong, (long long arg), (arg))
+    JSON_VALUE_WRITER_WRAP(WriteULongLong, (unsigned long long arg), (arg))
+    JSON_VALUE_WRITER_WRAP(WriteBool, (bool arg), (arg))
+    JSON_VALUE_WRITER_WRAP(WriteFloat, (float arg), (arg))
+    JSON_VALUE_WRITER_WRAP(WriteFloat, (float arg, EFloatToStringMode mode, int ndigits), (arg, mode, ndigits))
+    JSON_VALUE_WRITER_WRAP(WriteDouble, (double arg), (arg))
+    JSON_VALUE_WRITER_WRAP(WriteDouble, (double arg, EFloatToStringMode mode, int ndigits), (arg, mode, ndigits))
+    JSON_VALUE_WRITER_WRAP(WriteJsonValue, (const NJson::TJsonValue* value, bool sortKeys), (value, sortKeys))
+    JSON_VALUE_WRITER_WRAP(UnsafeWriteValue, (const TStringBuf& arg), (arg))
+#undef JSON_VALUE_WRITER_WRAP
+
+    template <typename TOutContext>
+    TValueContext TValueWriter<TOutContext>::BeginList() {
+        return Buf.BeginList();
+    }
+
+    template <typename TOutContext>
+    TPairContext TValueWriter<TOutContext>::BeginObject() {
+        return Buf.BeginObject();
+    }
+
+    TString WrapJsonToCallback(const TBuf& buf, TStringBuf callback);
+}