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