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Diffstat (limited to 'source/FastNBT.h')
| -rw-r--r-- | source/FastNBT.h | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/source/FastNBT.h b/source/FastNBT.h new file mode 100644 index 000000000..fd60fc671 --- /dev/null +++ b/source/FastNBT.h @@ -0,0 +1,234 @@ +
+// FastNBT.h
+
+// Interfaces to the fast NBT parser and writer
+
+/*
+The fast parser parses the data into a vector of cFastNBTTag structures. These structures describe the NBT tree,
+but themselves are allocated in a vector, thus minimizing reallocation.
+The structures have a minimal constructor, setting all member "pointers" to "invalid".
+
+The fast writer doesn't need a NBT tree structure built beforehand, it is commanded to open, append and close tags
+(just like XML); it keeps the internal tag stack and reports errors in usage.
+It directly outputs a string containing the serialized NBT data.
+*/
+
+
+
+
+
+#pragma once
+
+#include "Endianness.h"
+
+
+
+
+
+enum eTagType
+{
+ TAG_Min = 0, // The minimum value for a tag type
+ TAG_End = 0,
+ TAG_Byte = 1,
+ TAG_Short = 2,
+ TAG_Int = 3,
+ TAG_Long = 4,
+ TAG_Float = 5,
+ TAG_Double = 6,
+ TAG_ByteArray = 7,
+ TAG_String = 8,
+ TAG_List = 9,
+ TAG_Compound = 10,
+ TAG_IntArray = 11,
+ TAG_Max = 11, // The maximum value for a tag type
+} ;
+
+
+
+
+
+/** This structure is used for all NBT tags.
+It contains indices to the parent array of tags, building the NBT tree this way.
+Also contains indices into the data stream being parsed, used for values;
+NO dynamically allocated memory is used!
+Structure (all with the tree structure it describes) supports moving in memory (std::vector reallocation)
+*/
+struct cFastNBTTag
+{
+public:
+
+ eTagType m_Type;
+
+ // The following members are indices into the data stream. m_DataLength == 0 if no data available
+ // They must not be pointers, because the datastream may be copied into another AString object in the meantime.
+ int m_NameStart;
+ int m_NameLength;
+ int m_DataStart;
+ int m_DataLength;
+
+ // The following members are indices into the array returned; -1 if not valid
+ // They must not be pointers, because pointers would not survive std::vector reallocation
+ int m_Parent;
+ int m_PrevSibling;
+ int m_NextSibling;
+ int m_FirstChild;
+ int m_LastChild;
+
+ cFastNBTTag(eTagType a_Type, int a_Parent) :
+ m_Type(a_Type),
+ m_NameLength(0),
+ m_DataLength(0),
+ m_Parent(a_Parent),
+ m_PrevSibling(-1),
+ m_NextSibling(-1),
+ m_FirstChild(-1),
+ m_LastChild(-1)
+ {
+ }
+
+ cFastNBTTag(eTagType a_Type, int a_Parent, int a_PrevSibling) :
+ m_Type(a_Type),
+ m_NameLength(0),
+ m_DataLength(0),
+ m_Parent(a_Parent),
+ m_PrevSibling(a_PrevSibling),
+ m_NextSibling(-1),
+ m_FirstChild(-1),
+ m_LastChild(-1)
+ {
+ }
+} ;
+
+
+
+
+
+/** Parses and contains the parsed data
+Also implements data accessor functions for tree traversal and value getters
+The data pointer passed in the constructor is assumed to be valid throughout the object's life. Care must be taken not to initialize from a temporary.
+*/
+class cParsedNBT
+{
+public:
+ cParsedNBT(const char * a_Data, int a_Length);
+
+ bool IsValid(void) const {return m_IsValid; }
+
+ int GetRoot(void) const {return 0; }
+ int GetFirstChild (int a_Tag) const { return m_Tags[a_Tag].m_FirstChild; }
+ int GetLastChild (int a_Tag) const { return m_Tags[a_Tag].m_LastChild; }
+ int GetNextSibling(int a_Tag) const { return m_Tags[a_Tag].m_NextSibling; }
+ int GetPrevSibling(int a_Tag) const { return m_Tags[a_Tag].m_PrevSibling; }
+ int GetDataLength (int a_Tag) const { return m_Tags[a_Tag].m_DataLength; }
+
+ const char * GetData(int a_Tag) const
+ {
+ ASSERT(m_Tags[a_Tag].m_Type != TAG_List);
+ ASSERT(m_Tags[a_Tag].m_Type != TAG_Compound);
+ return m_Data + m_Tags[a_Tag].m_DataStart;
+ }
+
+ int FindChildByName(int a_Tag, const AString & a_Name) const
+ {
+ return FindChildByName(a_Tag, a_Name.c_str(), a_Name.length());
+ }
+
+ int FindChildByName(int a_Tag, const char * a_Name, size_t a_NameLength = 0) const;
+ int FindTagByPath (int a_Tag, const AString & a_Path) const;
+
+ eTagType GetType(int a_Tag) const { return m_Tags[a_Tag].m_Type; }
+
+ /// Returns the children type for a list tag; undefined on other tags. If list empty, returns TAG_End
+ eTagType GetChildrenType(int a_Tag) const
+ {
+ ASSERT(m_Tags[a_Tag].m_Type == TAG_List);
+ return (m_Tags[a_Tag].m_FirstChild < 0) ? TAG_End : m_Tags[m_Tags[a_Tag].m_FirstChild].m_Type;
+ }
+
+ inline unsigned char GetByte(int a_Tag) const
+ {
+ ASSERT(m_Tags[a_Tag].m_Type == TAG_Byte);
+ return (unsigned char)(m_Data[m_Tags[a_Tag].m_DataStart]);
+ }
+
+ inline Int16 GetShort(int a_Tag) const
+ {
+ ASSERT(m_Tags[a_Tag].m_Type == TAG_Short);
+ return ntohs(*((Int16 *)(m_Data + m_Tags[a_Tag].m_DataStart)));
+ }
+
+ inline Int32 GetInt(int a_Tag) const
+ {
+ ASSERT(m_Tags[a_Tag].m_Type == TAG_Int);
+ return ntohl(*((Int32 *)(m_Data + m_Tags[a_Tag].m_DataStart)));
+ }
+
+ inline Int64 GetLong(int a_Tag) const
+ {
+ ASSERT(m_Tags[a_Tag].m_Type == TAG_Long);
+ return NetworkToHostLong8(m_Data + m_Tags[a_Tag].m_DataStart);
+ }
+
+ inline float GetFloat(int a_Tag) const
+ {
+ ASSERT(m_Tags[a_Tag].m_Type == TAG_Float);
+ Int32 tmp = ntohl(*((Int32 *)(m_Data + m_Tags[a_Tag].m_DataStart)));
+ return *((float *)&tmp);
+ }
+
+ inline double GetDouble(int a_Tag) const
+ {
+ ASSERT(m_Tags[a_Tag].m_Type == TAG_Double);
+ return NetworkToHostDouble8(m_Data + m_Tags[a_Tag].m_DataStart);
+ }
+
+protected:
+ const char * m_Data;
+ int m_Length;
+ std::vector<cFastNBTTag> m_Tags;
+ bool m_IsValid; // True if parsing succeeded
+
+ // Used while parsing:
+ int m_Pos;
+
+ bool Parse(void);
+ bool ReadString(int & a_StringStart, int & a_StringLen); // Reads a simple string (2 bytes length + data), sets the string descriptors
+ bool ReadCompound(void); // Reads the latest tag as a compound
+ bool ReadList(eTagType a_ChildrenType); // Reads the latest tag as a list of items of type a_ChildrenType
+ bool ReadTag(void); // Reads the latest tag, depending on its m_Type setting
+} ;
+
+
+
+
+
+class cFastNBTWriter
+{
+public:
+ cFastNBTWriter(void);
+
+ void BeginCompound(const AString & a_Name);
+ void EndCompound(void);
+
+ void BeginList(const AString & a_Name, eTagType a_ChildrenType);
+ void EndList(void);
+
+ void AddByte (const AString & a_Name, unsigned char a_Value);
+ void AddShort (const AString & a_Name, unsigned char a_Value);
+ void AddInt (const AString & a_Name, unsigned char a_Value);
+ void AddLong (const AString & a_Name, unsigned char a_Value);
+ void AddFloat (const AString & a_Name, unsigned char a_Value);
+ void AddDouble (const AString & a_Name, unsigned char a_Value);
+ void AddString (const AString & a_Name, unsigned char a_Value);
+ void AddByteArray(const AString & a_Name, unsigned char a_Value);
+ void AddIntArray (const AString & a_Name, unsigned char a_Value);
+
+ const AString & GetResult(void) const {return m_Result; }
+
+protected:
+ AString m_Result;
+} ;
+
+
+
+
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