1 //===-- StringExtractor.h ---------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef utility_StringExtractor_h_
10 #define utility_StringExtractor_h_
11 
12 #include "llvm/ADT/ArrayRef.h"
13 #include "llvm/ADT/StringRef.h"
14 
15 #include <stddef.h>
16 #include <stdint.h>
17 #include <string>
18 
19 class StringExtractor {
20 public:
21   enum { BigEndian = 0, LittleEndian = 1 };
22   // Constructors and Destructors
23   StringExtractor();
24   StringExtractor(llvm::StringRef packet_str);
25   StringExtractor(const char *packet_cstr);
26   virtual ~StringExtractor();
27 
28   void Reset(llvm::StringRef str) {
29     m_packet = str;
30     m_index = 0;
31   }
32 
33   // Returns true if the file position is still valid for the data contained in
34   // this string extractor object.
35   bool IsGood() const { return m_index != UINT64_MAX; }
36 
37   uint64_t GetFilePos() const { return m_index; }
38 
39   void SetFilePos(uint32_t idx) { m_index = idx; }
40 
41   void Clear() {
42     m_packet.clear();
43     m_index = 0;
44   }
45 
46   void SkipSpaces();
47 
48   std::string &GetStringRef() { return m_packet; }
49 
50   const std::string &GetStringRef() const { return m_packet; }
51 
52   bool Empty() { return m_packet.empty(); }
53 
54   size_t GetBytesLeft() {
55     if (m_index < m_packet.size())
56       return m_packet.size() - m_index;
57     return 0;
58   }
59 
60   char GetChar(char fail_value = '\0');
61 
62   char PeekChar(char fail_value = '\0') {
63     const char *cstr = Peek();
64     if (cstr)
65       return cstr[0];
66     return fail_value;
67   }
68 
69   int DecodeHexU8();
70 
71   uint8_t GetHexU8(uint8_t fail_value = 0, bool set_eof_on_fail = true);
72 
73   bool GetHexU8Ex(uint8_t &ch, bool set_eof_on_fail = true);
74 
75   bool GetNameColonValue(llvm::StringRef &name, llvm::StringRef &value);
76 
77   int32_t GetS32(int32_t fail_value, int base = 0);
78 
79   uint32_t GetU32(uint32_t fail_value, int base = 0);
80 
81   int64_t GetS64(int64_t fail_value, int base = 0);
82 
83   uint64_t GetU64(uint64_t fail_value, int base = 0);
84 
85   uint32_t GetHexMaxU32(bool little_endian, uint32_t fail_value);
86 
87   uint64_t GetHexMaxU64(bool little_endian, uint64_t fail_value);
88 
89   size_t GetHexBytes(llvm::MutableArrayRef<uint8_t> dest,
90                      uint8_t fail_fill_value);
91 
92   size_t GetHexBytesAvail(llvm::MutableArrayRef<uint8_t> dest);
93 
94   uint64_t GetHexWithFixedSize(uint32_t byte_size, bool little_endian,
95                                uint64_t fail_value);
96 
97   size_t GetHexByteString(std::string &str);
98 
99   size_t GetHexByteStringFixedLength(std::string &str, uint32_t nibble_length);
100 
101   size_t GetHexByteStringTerminatedBy(std::string &str, char terminator);
102 
103   bool ConsumeFront(const llvm::StringRef &str);
104 
105   const char *Peek() {
106     if (m_index < m_packet.size())
107       return m_packet.c_str() + m_index;
108     return nullptr;
109   }
110 
111 protected:
112   bool fail() {
113     m_index = UINT64_MAX;
114     return false;
115   }
116   // For StringExtractor only
117   std::string m_packet; // The string in which to extract data.
118   uint64_t m_index;     // When extracting data from a packet, this index
119                         // will march along as things get extracted. If set to
120                         // UINT64_MAX the end of the packet data was reached
121                         // when decoding information
122 };
123 
124 #endif // utility_StringExtractor_h_
125