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      1 // Copyright 2014 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef V8_STRING_STREAM_H_
      6 #define V8_STRING_STREAM_H_
      7 
      8 #include <memory>
      9 
     10 #include "src/allocation.h"
     11 #include "src/handles.h"
     12 #include "src/vector.h"
     13 
     14 namespace v8 {
     15 namespace internal {
     16 
     17 // Forward declarations.
     18 class ByteArray;
     19 
     20 class StringAllocator {
     21  public:
     22   virtual ~StringAllocator() { }
     23   // Allocate a number of bytes.
     24   virtual char* allocate(unsigned bytes) = 0;
     25   // Allocate a larger number of bytes and copy the old buffer to the new one.
     26   // bytes is an input and output parameter passing the old size of the buffer
     27   // and returning the new size.  If allocation fails then we return the old
     28   // buffer and do not increase the size.
     29   virtual char* grow(unsigned* bytes) = 0;
     30 };
     31 
     32 
     33 // Normal allocator uses new[] and delete[].
     34 class HeapStringAllocator final : public StringAllocator {
     35  public:
     36   ~HeapStringAllocator() { DeleteArray(space_); }
     37   char* allocate(unsigned bytes) override;
     38   char* grow(unsigned* bytes) override;
     39 
     40  private:
     41   char* space_;
     42 };
     43 
     44 
     45 class FixedStringAllocator final : public StringAllocator {
     46  public:
     47   FixedStringAllocator(char* buffer, unsigned length)
     48       : buffer_(buffer), length_(length) {}
     49   ~FixedStringAllocator() override{};
     50   char* allocate(unsigned bytes) override;
     51   char* grow(unsigned* bytes) override;
     52 
     53  private:
     54   char* buffer_;
     55   unsigned length_;
     56   DISALLOW_COPY_AND_ASSIGN(FixedStringAllocator);
     57 };
     58 
     59 
     60 class FmtElm final {
     61  public:
     62   FmtElm(int value) : type_(INT) {  // NOLINT
     63     data_.u_int_ = value;
     64   }
     65   explicit FmtElm(double value) : type_(DOUBLE) {
     66     data_.u_double_ = value;
     67   }
     68   FmtElm(const char* value) : type_(C_STR) {  // NOLINT
     69     data_.u_c_str_ = value;
     70   }
     71   FmtElm(const Vector<const uc16>& value) : type_(LC_STR) {  // NOLINT
     72     data_.u_lc_str_ = &value;
     73   }
     74   FmtElm(Object* value) : type_(OBJ) {  // NOLINT
     75     data_.u_obj_ = value;
     76   }
     77   FmtElm(Handle<Object> value) : type_(HANDLE) {  // NOLINT
     78     data_.u_handle_ = value.location();
     79   }
     80   FmtElm(void* value) : type_(POINTER) {  // NOLINT
     81     data_.u_pointer_ = value;
     82   }
     83 
     84  private:
     85   friend class StringStream;
     86   enum Type { INT, DOUBLE, C_STR, LC_STR, OBJ, HANDLE, POINTER };
     87   Type type_;
     88   union {
     89     int u_int_;
     90     double u_double_;
     91     const char* u_c_str_;
     92     const Vector<const uc16>* u_lc_str_;
     93     Object* u_obj_;
     94     Object** u_handle_;
     95     void* u_pointer_;
     96   } data_;
     97 };
     98 
     99 
    100 class StringStream final {
    101  public:
    102   enum ObjectPrintMode { kPrintObjectConcise, kPrintObjectVerbose };
    103   StringStream(StringAllocator* allocator,
    104                ObjectPrintMode object_print_mode = kPrintObjectVerbose)
    105       : allocator_(allocator),
    106         object_print_mode_(object_print_mode),
    107         capacity_(kInitialCapacity),
    108         length_(0),
    109         buffer_(allocator_->allocate(kInitialCapacity)) {
    110     buffer_[0] = 0;
    111   }
    112 
    113   bool Put(char c);
    114   bool Put(String* str);
    115   bool Put(String* str, int start, int end);
    116   void Add(Vector<const char> format, Vector<FmtElm> elms);
    117   void Add(const char* format);
    118   void Add(Vector<const char> format);
    119   void Add(const char* format, FmtElm arg0);
    120   void Add(const char* format, FmtElm arg0, FmtElm arg1);
    121   void Add(const char* format, FmtElm arg0, FmtElm arg1, FmtElm arg2);
    122   void Add(const char* format,
    123            FmtElm arg0,
    124            FmtElm arg1,
    125            FmtElm arg2,
    126            FmtElm arg3);
    127   void Add(const char* format,
    128            FmtElm arg0,
    129            FmtElm arg1,
    130            FmtElm arg2,
    131            FmtElm arg3,
    132            FmtElm arg4);
    133 
    134   // Getting the message out.
    135   void OutputToFile(FILE* out);
    136   void OutputToStdOut() { OutputToFile(stdout); }
    137   void Log(Isolate* isolate);
    138   Handle<String> ToString(Isolate* isolate);
    139   std::unique_ptr<char[]> ToCString() const;
    140   int length() const { return length_; }
    141 
    142   // Object printing support.
    143   void PrintName(Object* o);
    144   void PrintFixedArray(FixedArray* array, unsigned int limit);
    145   void PrintByteArray(ByteArray* ba);
    146   void PrintUsingMap(JSObject* js_object);
    147   void PrintPrototype(JSFunction* fun, Object* receiver);
    148   void PrintSecurityTokenIfChanged(Object* function);
    149   // NOTE: Returns the code in the output parameter.
    150   void PrintFunction(Object* function, Object* receiver, Code** code);
    151 
    152   // Reset the stream.
    153   void Reset() {
    154     length_ = 0;
    155     buffer_[0] = 0;
    156   }
    157 
    158   // Mentioned object cache support.
    159   void PrintMentionedObjectCache(Isolate* isolate);
    160   static void ClearMentionedObjectCache(Isolate* isolate);
    161 #ifdef DEBUG
    162   bool IsMentionedObjectCacheClear(Isolate* isolate);
    163 #endif
    164 
    165   static const int kInitialCapacity = 16;
    166 
    167  private:
    168   void PrintObject(Object* obj);
    169 
    170   StringAllocator* allocator_;
    171   ObjectPrintMode object_print_mode_;
    172   unsigned capacity_;
    173   unsigned length_;  // does not include terminating 0-character
    174   char* buffer_;
    175 
    176   bool full() const { return (capacity_ - length_) == 1; }
    177   int space() const { return capacity_ - length_; }
    178 
    179   DISALLOW_IMPLICIT_CONSTRUCTORS(StringStream);
    180 };
    181 
    182 }  // namespace internal
    183 }  // namespace v8
    184 
    185 #endif  // V8_STRING_STREAM_H_
    186