Move base to DEPS

base/values.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// This file specifies a recursive data storage class called Value intended for
-// storing settings and other persistable data.
-//
-// A Value represents something that can be stored in JSON or passed to/from
-// JavaScript. As such, it is NOT a generalized variant type, since only the
-// types supported by JavaScript/JSON are supported.
-//
-// IN PARTICULAR this means that there is no support for int64 or unsigned
-// numbers. Writing JSON with such types would violate the spec. If you need
-// something like this, either use a double or make a string value containing
-// the number you want.
-
-#ifndef BASE_VALUES_H_
-#define BASE_VALUES_H_
-
-#include <stddef.h>
-
-#include <iosfwd>
-#include <map>
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "base/base_export.h"
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/strings/string16.h"
-#include "base/strings/string_piece.h"
-
-namespace base {
-
-class BinaryValue;
-class DictionaryValue;
-class FundamentalValue;
-class ListValue;
-class StringValue;
-class Value;
-
-typedef std::vector<Value*> ValueVector;
-typedef std::map<std::string, Value*> ValueMap;
-
-// The Value class is the base class for Values. A Value can be instantiated
-// via the Create*Value() factory methods, or by directly creating instances of
-// the subclasses.
-//
-// See the file-level comment above for more information.
-class BASE_EXPORT Value {
- public:
-  enum Type {
-    TYPE_NULL = 0,
-    TYPE_BOOLEAN,
-    TYPE_INTEGER,
-    TYPE_DOUBLE,
-    TYPE_STRING,
-    TYPE_BINARY,
-    TYPE_DICTIONARY,
-    TYPE_LIST
-    // Note: Do not add more types. See the file-level comment above for why.
-  };
-
-  virtual ~Value();
-
-  static scoped_ptr<Value> CreateNullValue();
-
-  // Returns the type of the value stored by the current Value object.
-  // Each type will be implemented by only one subclass of Value, so it's
-  // safe to use the Type to determine whether you can cast from
-  // Value* to (Implementing Class)*.  Also, a Value object never changes
-  // its type after construction.
-  Type GetType() const { return type_; }
-
-  // Returns true if the current object represents a given type.
-  bool IsType(Type type) const { return type == type_; }
-
-  // These methods allow the convenient retrieval of the contents of the Value.
-  // If the current object can be converted into the given type, the value is
-  // returned through the |out_value| parameter and true is returned;
-  // otherwise, false is returned and |out_value| is unchanged.
-  virtual bool GetAsBoolean(bool* out_value) const;
-  virtual bool GetAsInteger(int* out_value) const;
-  virtual bool GetAsDouble(double* out_value) const;
-  virtual bool GetAsString(std::string* out_value) const;
-  virtual bool GetAsString(string16* out_value) const;
-  virtual bool GetAsString(const StringValue** out_value) const;
-  virtual bool GetAsBinary(const BinaryValue** out_value) const;
-  virtual bool GetAsList(ListValue** out_value);
-  virtual bool GetAsList(const ListValue** out_value) const;
-  virtual bool GetAsDictionary(DictionaryValue** out_value);
-  virtual bool GetAsDictionary(const DictionaryValue** out_value) const;
-  // Note: Do not add more types. See the file-level comment above for why.
-
-  // This creates a deep copy of the entire Value tree, and returns a pointer
-  // to the copy.  The caller gets ownership of the copy, of course.
-  //
-  // Subclasses return their own type directly in their overrides;
-  // this works because C++ supports covariant return types.
-  virtual Value* DeepCopy() const;
-  // Preferred version of DeepCopy. TODO(estade): remove the above.
-  scoped_ptr<Value> CreateDeepCopy() const;
-
-  // Compares if two Value objects have equal contents.
-  virtual bool Equals(const Value* other) const;
-
-  // Compares if two Value objects have equal contents. Can handle NULLs.
-  // NULLs are considered equal but different from Value::CreateNullValue().
-  static bool Equals(const Value* a, const Value* b);
-
- protected:
-  // These aren't safe for end-users, but they are useful for subclasses.
-  explicit Value(Type type);
-  Value(const Value& that);
-  Value& operator=(const Value& that);
-
- private:
-  Type type_;
-};
-
-// FundamentalValue represents the simple fundamental types of values.
-class BASE_EXPORT FundamentalValue : public Value {
- public:
-  explicit FundamentalValue(bool in_value);
-  explicit FundamentalValue(int in_value);
-  explicit FundamentalValue(double in_value);
-  ~FundamentalValue() override;
-
-  // Overridden from Value:
-  bool GetAsBoolean(bool* out_value) const override;
-  bool GetAsInteger(int* out_value) const override;
-  // Values of both type TYPE_INTEGER and TYPE_DOUBLE can be obtained as
-  // doubles.
-  bool GetAsDouble(double* out_value) const override;
-  FundamentalValue* DeepCopy() const override;
-  bool Equals(const Value* other) const override;
-
- private:
-  union {
-    bool boolean_value_;
-    int integer_value_;
-    double double_value_;
-  };
-};
-
-class BASE_EXPORT StringValue : public Value {
- public:
-  // Initializes a StringValue with a UTF-8 narrow character string.
-  explicit StringValue(const std::string& in_value);
-
-  // Initializes a StringValue with a string16.
-  explicit StringValue(const string16& in_value);
-
-  ~StringValue() override;
-
-  // Returns |value_| as a pointer or reference.
-  std::string* GetString();
-  const std::string& GetString() const;
-
-  // Overridden from Value:
-  bool GetAsString(std::string* out_value) const override;
-  bool GetAsString(string16* out_value) const override;
-  bool GetAsString(const StringValue** out_value) const override;
-  StringValue* DeepCopy() const override;
-  bool Equals(const Value* other) const override;
-
- private:
-  std::string value_;
-};
-
-class BASE_EXPORT BinaryValue: public Value {
- public:
-  // Creates a BinaryValue with a null buffer and size of 0.
-  BinaryValue();
-
-  // Creates a BinaryValue, taking ownership of the bytes pointed to by
-  // |buffer|.
-  BinaryValue(scoped_ptr<char[]> buffer, size_t size);
-
-  ~BinaryValue() override;
-
-  // For situations where you want to keep ownership of your buffer, this
-  // factory method creates a new BinaryValue by copying the contents of the
-  // buffer that's passed in.
-  static BinaryValue* CreateWithCopiedBuffer(const char* buffer, size_t size);
-
-  size_t GetSize() const { return size_; }
-
-  // May return NULL.
-  char* GetBuffer() { return buffer_.get(); }
-  const char* GetBuffer() const { return buffer_.get(); }
-
-  // Overridden from Value:
-  bool GetAsBinary(const BinaryValue** out_value) const override;
-  BinaryValue* DeepCopy() const override;
-  bool Equals(const Value* other) const override;
-
- private:
-  scoped_ptr<char[]> buffer_;
-  size_t size_;
-
-  DISALLOW_COPY_AND_ASSIGN(BinaryValue);
-};
-
-// DictionaryValue provides a key-value dictionary with (optional) "path"
-// parsing for recursive access; see the comment at the top of the file. Keys
-// are |std::string|s and should be UTF-8 encoded.
-class BASE_EXPORT DictionaryValue : public Value {
- public:
-  DictionaryValue();
-  ~DictionaryValue() override;
-
-  // Overridden from Value:
-  bool GetAsDictionary(DictionaryValue** out_value) override;
-  bool GetAsDictionary(const DictionaryValue** out_value) const override;
-
-  // Returns true if the current dictionary has a value for the given key.
-  bool HasKey(const std::string& key) const;
-
-  // Returns the number of Values in this dictionary.
-  size_t size() const { return dictionary_.size(); }
-
-  // Returns whether the dictionary is empty.
-  bool empty() const { return dictionary_.empty(); }
-
-  // Clears any current contents of this dictionary.
-  void Clear();
-
-  // Sets the Value associated with the given path starting from this object.
-  // A path has the form "<key>" or "<key>.<key>.[...]", where "." indexes
-  // into the next DictionaryValue down.  Obviously, "." can't be used
-  // within a key, but there are no other restrictions on keys.
-  // If the key at any step of the way doesn't exist, or exists but isn't
-  // a DictionaryValue, a new DictionaryValue will be created and attached
-  // to the path in that location. |in_value| must be non-null.
-  void Set(const std::string& path, scoped_ptr<Value> in_value);
-  // Deprecated version of the above. TODO(estade): remove.
-  void Set(const std::string& path, Value* in_value);
-
-  // Convenience forms of Set().  These methods will replace any existing
-  // value at that path, even if it has a different type.
-  void SetBoolean(const std::string& path, bool in_value);
-  void SetInteger(const std::string& path, int in_value);
-  void SetDouble(const std::string& path, double in_value);
-  void SetString(const std::string& path, const std::string& in_value);
-  void SetString(const std::string& path, const string16& in_value);
-
-  // Like Set(), but without special treatment of '.'.  This allows e.g. URLs to
-  // be used as paths.
-  void SetWithoutPathExpansion(const std::string& key,
-                               scoped_ptr<Value> in_value);
-  // Deprecated version of the above. TODO(estade): remove.
-  void SetWithoutPathExpansion(const std::string& key, Value* in_value);
-
-  // Convenience forms of SetWithoutPathExpansion().
-  void SetBooleanWithoutPathExpansion(const std::string& path, bool in_value);
-  void SetIntegerWithoutPathExpansion(const std::string& path, int in_value);
-  void SetDoubleWithoutPathExpansion(const std::string& path, double in_value);
-  void SetStringWithoutPathExpansion(const std::string& path,
-                                     const std::string& in_value);
-  void SetStringWithoutPathExpansion(const std::string& path,
-                                     const string16& in_value);
-
-  // Gets the Value associated with the given path starting from this object.
-  // A path has the form "<key>" or "<key>.<key>.[...]", where "." indexes
-  // into the next DictionaryValue down.  If the path can be resolved
-  // successfully, the value for the last key in the path will be returned
-  // through the |out_value| parameter, and the function will return true.
-  // Otherwise, it will return false and |out_value| will be untouched.
-  // Note that the dictionary always owns the value that's returned.
-  // |out_value| is optional and will only be set if non-NULL.
-  bool Get(StringPiece path, const Value** out_value) const;
-  bool Get(StringPiece path, Value** out_value);
-
-  // These are convenience forms of Get().  The value will be retrieved
-  // and the return value will be true if the path is valid and the value at
-  // the end of the path can be returned in the form specified.
-  // |out_value| is optional and will only be set if non-NULL.
-  bool GetBoolean(const std::string& path, bool* out_value) const;
-  bool GetInteger(const std::string& path, int* out_value) const;
-  // Values of both type TYPE_INTEGER and TYPE_DOUBLE can be obtained as
-  // doubles.
-  bool GetDouble(const std::string& path, double* out_value) const;
-  bool GetString(const std::string& path, std::string* out_value) const;
-  bool GetString(const std::string& path, string16* out_value) const;
-  bool GetStringASCII(const std::string& path, std::string* out_value) const;
-  bool GetBinary(const std::string& path, const BinaryValue** out_value) const;
-  bool GetBinary(const std::string& path, BinaryValue** out_value);
-  bool GetDictionary(StringPiece path, const DictionaryValue** out_value) const;
-  bool GetDictionary(StringPiece path, DictionaryValue** out_value);
-  bool GetList(const std::string& path, const ListValue** out_value) const;
-  bool GetList(const std::string& path, ListValue** out_value);
-
-  // Like Get(), but without special treatment of '.'.  This allows e.g. URLs to
-  // be used as paths.
-  bool GetWithoutPathExpansion(const std::string& key,
-                               const Value** out_value) const;
-  bool GetWithoutPathExpansion(const std::string& key, Value** out_value);
-  bool GetBooleanWithoutPathExpansion(const std::string& key,
-                                      bool* out_value) const;
-  bool GetIntegerWithoutPathExpansion(const std::string& key,
-                                      int* out_value) const;
-  bool GetDoubleWithoutPathExpansion(const std::string& key,
-                                     double* out_value) const;
-  bool GetStringWithoutPathExpansion(const std::string& key,
-                                     std::string* out_value) const;
-  bool GetStringWithoutPathExpansion(const std::string& key,
-                                     string16* out_value) const;
-  bool GetDictionaryWithoutPathExpansion(
-      const std::string& key,
-      const DictionaryValue** out_value) const;
-  bool GetDictionaryWithoutPathExpansion(const std::string& key,
-                                         DictionaryValue** out_value);
-  bool GetListWithoutPathExpansion(const std::string& key,
-                                   const ListValue** out_value) const;
-  bool GetListWithoutPathExpansion(const std::string& key,
-                                   ListValue** out_value);
-
-  // Removes the Value with the specified path from this dictionary (or one
-  // of its child dictionaries, if the path is more than just a local key).
-  // If |out_value| is non-NULL, the removed Value will be passed out via
-  // |out_value|.  If |out_value| is NULL, the removed value will be deleted.
-  // This method returns true if |path| is a valid path; otherwise it will
-  // return false and the DictionaryValue object will be unchanged.
-  virtual bool Remove(const std::string& path, scoped_ptr<Value>* out_value);
-
-  // Like Remove(), but without special treatment of '.'.  This allows e.g. URLs
-  // to be used as paths.
-  virtual bool RemoveWithoutPathExpansion(const std::string& key,
-                                          scoped_ptr<Value>* out_value);
-
-  // Removes a path, clearing out all dictionaries on |path| that remain empty
-  // after removing the value at |path|.
-  virtual bool RemovePath(const std::string& path,
-                          scoped_ptr<Value>* out_value);
-
-  // Makes a copy of |this| but doesn't include empty dictionaries and lists in
-  // the copy.  This never returns NULL, even if |this| itself is empty.
-  scoped_ptr<DictionaryValue> DeepCopyWithoutEmptyChildren() const;
-
-  // Merge |dictionary| into this dictionary. This is done recursively, i.e. any
-  // sub-dictionaries will be merged as well. In case of key collisions, the
-  // passed in dictionary takes precedence and data already present will be
-  // replaced. Values within |dictionary| are deep-copied, so |dictionary| may
-  // be freed any time after this call.
-  void MergeDictionary(const DictionaryValue* dictionary);
-
-  // Swaps contents with the |other| dictionary.
-  virtual void Swap(DictionaryValue* other);
-
-  // This class provides an iterator over both keys and values in the
-  // dictionary.  It can't be used to modify the dictionary.
-  class BASE_EXPORT Iterator {
-   public:
-    explicit Iterator(const DictionaryValue& target);
-    ~Iterator();
-
-    bool IsAtEnd() const { return it_ == target_.dictionary_.end(); }
-    void Advance() { ++it_; }
-
-    const std::string& key() const { return it_->first; }
-    const Value& value() const { return *it_->second; }
-
-   private:
-    const DictionaryValue& target_;
-    ValueMap::const_iterator it_;
-  };
-
-  // Overridden from Value:
-  DictionaryValue* DeepCopy() const override;
-  // Preferred version of DeepCopy. TODO(estade): remove the above.
-  scoped_ptr<DictionaryValue> CreateDeepCopy() const;
-  bool Equals(const Value* other) const override;
-
- private:
-  ValueMap dictionary_;
-
-  DISALLOW_COPY_AND_ASSIGN(DictionaryValue);
-};
-
-// This type of Value represents a list of other Value values.
-class BASE_EXPORT ListValue : public Value {
- public:
-  typedef ValueVector::iterator iterator;
-  typedef ValueVector::const_iterator const_iterator;
-
-  ListValue();
-  ~ListValue() override;
-
-  // Clears the contents of this ListValue
-  void Clear();
-
-  // Returns the number of Values in this list.
-  size_t GetSize() const { return list_.size(); }
-
-  // Returns whether the list is empty.
-  bool empty() const { return list_.empty(); }
-
-  // Sets the list item at the given index to be the Value specified by
-  // the value given.  If the index beyond the current end of the list, null
-  // Values will be used to pad out the list.
-  // Returns true if successful, or false if the index was negative or
-  // the value is a null pointer.
-  bool Set(size_t index, Value* in_value);
-  // Preferred version of the above. TODO(estade): remove the above.
-  bool Set(size_t index, scoped_ptr<Value> in_value);
-
-  // Gets the Value at the given index.  Modifies |out_value| (and returns true)
-  // only if the index falls within the current list range.
-  // Note that the list always owns the Value passed out via |out_value|.
-  // |out_value| is optional and will only be set if non-NULL.
-  bool Get(size_t index, const Value** out_value) const;
-  bool Get(size_t index, Value** out_value);
-
-  // Convenience forms of Get().  Modifies |out_value| (and returns true)
-  // only if the index is valid and the Value at that index can be returned
-  // in the specified form.
-  // |out_value| is optional and will only be set if non-NULL.
-  bool GetBoolean(size_t index, bool* out_value) const;
-  bool GetInteger(size_t index, int* out_value) const;
-  // Values of both type TYPE_INTEGER and TYPE_DOUBLE can be obtained as
-  // doubles.
-  bool GetDouble(size_t index, double* out_value) const;
-  bool GetString(size_t index, std::string* out_value) const;
-  bool GetString(size_t index, string16* out_value) const;
-  bool GetBinary(size_t index, const BinaryValue** out_value) const;
-  bool GetBinary(size_t index, BinaryValue** out_value);
-  bool GetDictionary(size_t index, const DictionaryValue** out_value) const;
-  bool GetDictionary(size_t index, DictionaryValue** out_value);
-  bool GetList(size_t index, const ListValue** out_value) const;
-  bool GetList(size_t index, ListValue** out_value);
-
-  // Removes the Value with the specified index from this list.
-  // If |out_value| is non-NULL, the removed Value AND ITS OWNERSHIP will be
-  // passed out via |out_value|.  If |out_value| is NULL, the removed value will
-  // be deleted.  This method returns true if |index| is valid; otherwise
-  // it will return false and the ListValue object will be unchanged.
-  virtual bool Remove(size_t index, scoped_ptr<Value>* out_value);
-
-  // Removes the first instance of |value| found in the list, if any, and
-  // deletes it. |index| is the location where |value| was found. Returns false
-  // if not found.
-  bool Remove(const Value& value, size_t* index);
-
-  // Removes the element at |iter|. If |out_value| is NULL, the value will be
-  // deleted, otherwise ownership of the value is passed back to the caller.
-  // Returns an iterator pointing to the location of the element that
-  // followed the erased element.
-  iterator Erase(iterator iter, scoped_ptr<Value>* out_value);
-
-  // Appends a Value to the end of the list.
-  void Append(scoped_ptr<Value> in_value);
-  // Deprecated version of the above. TODO(estade): remove.
-  void Append(Value* in_value);
-
-  // Convenience forms of Append.
-  void AppendBoolean(bool in_value);
-  void AppendInteger(int in_value);
-  void AppendDouble(double in_value);
-  void AppendString(const std::string& in_value);
-  void AppendString(const string16& in_value);
-  void AppendStrings(const std::vector<std::string>& in_values);
-  void AppendStrings(const std::vector<string16>& in_values);
-
-  // Appends a Value if it's not already present. Takes ownership of the
-  // |in_value|. Returns true if successful, or false if the value was already
-  // present. If the value was already present the |in_value| is deleted.
-  bool AppendIfNotPresent(Value* in_value);
-
-  // Insert a Value at index.
-  // Returns true if successful, or false if the index was out of range.
-  bool Insert(size_t index, Value* in_value);
-
-  // Searches for the first instance of |value| in the list using the Equals
-  // method of the Value type.
-  // Returns a const_iterator to the found item or to end() if none exists.
-  const_iterator Find(const Value& value) const;
-
-  // Swaps contents with the |other| list.
-  virtual void Swap(ListValue* other);
-
-  // Iteration.
-  iterator begin() { return list_.begin(); }
-  iterator end() { return list_.end(); }
-
-  const_iterator begin() const { return list_.begin(); }
-  const_iterator end() const { return list_.end(); }
-
-  // Overridden from Value:
-  bool GetAsList(ListValue** out_value) override;
-  bool GetAsList(const ListValue** out_value) const override;
-  ListValue* DeepCopy() const override;
-  bool Equals(const Value* other) const override;
-
-  // Preferred version of DeepCopy. TODO(estade): remove DeepCopy.
-  scoped_ptr<ListValue> CreateDeepCopy() const;
-
- private:
-  ValueVector list_;
-
-  DISALLOW_COPY_AND_ASSIGN(ListValue);
-};
-
-// This interface is implemented by classes that know how to serialize
-// Value objects.
-class BASE_EXPORT ValueSerializer {
- public:
-  virtual ~ValueSerializer();
-
-  virtual bool Serialize(const Value& root) = 0;
-};
-
-// This interface is implemented by classes that know how to deserialize Value
-// objects.
-class BASE_EXPORT ValueDeserializer {
- public:
-  virtual ~ValueDeserializer();
-
-  // This method deserializes the subclass-specific format into a Value object.
-  // If the return value is non-NULL, the caller takes ownership of returned
-  // Value. If the return value is NULL, and if error_code is non-NULL,
-  // error_code will be set with the underlying error.
-  // If |error_message| is non-null, it will be filled in with a formatted
-  // error message including the location of the error if appropriate.
-  virtual Value* Deserialize(int* error_code, std::string* error_str) = 0;
-};
-
-// Stream operator so Values can be used in assertion statements.  In order that
-// gtest uses this operator to print readable output on test failures, we must
-// override each specific type. Otherwise, the default template implementation
-// is preferred over an upcast.
-BASE_EXPORT std::ostream& operator<<(std::ostream& out, const Value& value);
-
-BASE_EXPORT inline std::ostream& operator<<(std::ostream& out,
-                                            const FundamentalValue& value) {
-  return out << static_cast<const Value&>(value);
-}
-
-BASE_EXPORT inline std::ostream& operator<<(std::ostream& out,
-                                            const StringValue& value) {
-  return out << static_cast<const Value&>(value);
-}
-
-BASE_EXPORT inline std::ostream& operator<<(std::ostream& out,
-                                            const DictionaryValue& value) {
-  return out << static_cast<const Value&>(value);
-}
-
-BASE_EXPORT inline std::ostream& operator<<(std::ostream& out,
-                                            const ListValue& value) {
-  return out << static_cast<const Value&>(value);
-}
-
-}  // namespace base
-
-#endif  // BASE_VALUES_H_