LibCBOR/Include/CBOR/Decoder.hpp

@@ -4,7 +4,6 @@
 #include "Core.hpp"
 
 #include <span>
-#include <string_view>
 
 namespace CBOR
 {
@@ -126,6 +125,8 @@ namespace CBOR
         Item Next();
 
     private:
+        static constexpr std::size_t Indefinite = std::numeric_limits<std::size_t>::max();
+
         friend class Decoder;
 
         bool        mHeaderParsed;
@@ -146,6 +147,8 @@ namespace CBOR
         KeyValue Next();
 
     private:
+        static constexpr std::size_t Indefinite = std::numeric_limits<std::size_t>::max();
+
         friend class Decoder;
 
         bool        mHeaderParsed;
@@ -189,6 +192,26 @@ namespace CBOR
         friend class Array;
         friend class Map;
 
+        enum class State: std::uint8_t
+        {
+            Initial,
+            HeaderExtracted,
+        };
+
+        struct Header
+        {
+            MajorType        Type;
+            MinorType        Minor;
+            ArgumentPosition ArgPosition;
+            std::uint64_t    Argument;
+        };
+        Header PeekHeader();
+        Header ExtractHeader();
+
+        std::span<std::uint8_t> ExtractBinary(std::size_t size);
+        std::string_view        ExtractString(std::size_t size);
+
+        State                   mState;
         std::size_t             mCurrent;
         std::span<std::uint8_t> mBuffer;
     };

LibCBOR/Source/Decoder.cpp

@@ -15,6 +15,14 @@
 
 namespace CBOR
 {
+    class ImplementationError: public DecodeError
+    {
+    public:
+        ImplementationError(std::string_view message)
+            : DecodeError(std::string("internal implementation error: ").append(message))
+        {}
+    };
+
     class InvalidUsageError: public DecodeError
     {
     public:
@@ -55,8 +63,6 @@ namespace CBOR
 
     namespace
     {
-        static constexpr std::size_t Indefinite = std::numeric_limits<std::size_t>::max();
-
         std::size_t SpaceLeft(std::span<std::uint8_t> buffer, std::size_t offset)
         {
             if (offset >= buffer.size()) {
@@ -81,6 +87,41 @@ namespace CBOR
             return buffer[current];
         }
 
+        std::uint16_t Read2B(std::span<std::uint8_t> buffer, std::size_t current)
+        {
+            EnsureEnoughSpace(buffer, current, 2);
+            std::uint16_t result = 0;
+            result |= std::uint16_t(buffer[current    ])     ;
+            result |= std::uint16_t(buffer[current + 1]) << 8;
+            return NetworkToHost(result);
+        }
+
+        std::uint32_t Read4B(std::span<std::uint8_t> buffer, std::size_t current)
+        {
+            EnsureEnoughSpace(buffer, current, 4);
+            std::uint32_t result = 0;
+            result |= std::uint32_t(buffer[current    ])      ;
+            result |= std::uint32_t(buffer[current + 1]) <<  8;
+            result |= std::uint32_t(buffer[current + 2]) << 16;
+            result |= std::uint32_t(buffer[current + 3]) << 24;
+            return NetworkToHost(result);
+        }
+
+        std::uint64_t Read8B(std::span<std::uint8_t> buffer, std::size_t current)
+        {
+            EnsureEnoughSpace(buffer, current, 8);
+            std::uint64_t result = 0;
+            result |= std::uint64_t(buffer[current    ])      ;
+            result |= std::uint64_t(buffer[current + 1]) <<  8;
+            result |= std::uint64_t(buffer[current + 2]) << 16;
+            result |= std::uint64_t(buffer[current + 3]) << 24;
+            result |= std::uint64_t(buffer[current + 4]) << 32;
+            result |= std::uint64_t(buffer[current + 5]) << 40;
+            result |= std::uint64_t(buffer[current + 6]) << 48;
+            result |= std::uint64_t(buffer[current + 7]) << 56;
+            return NetworkToHost(result);
+        }
+
         std::uint8_t  Consume1B(std::span<std::uint8_t> buffer, std::size_t &current)
         {
             EnsureEnoughSpace(buffer, current, 1);
@@ -137,27 +178,6 @@ namespace CBOR
             return ArgumentPosition(header & std::to_underlying(ArgumentPosition::PositionMask));
         }
 
-        std::uint64_t ArgumentValue(std::uint8_t header, std::span<std::uint8_t> buffer, std::size_t &current)
-        {
-            ArgumentPosition pos = GetArgumentPosition(header);
-            if (std::to_underlying(pos) <= 23) {
-                return std::to_underlying(pos);
-            }
-            switch (pos) {
-            case ArgumentPosition::Next1B:
-                return Consume1B(buffer, current);
-            case ArgumentPosition::Next2B:
-                return Consume2B(buffer, current);
-            case ArgumentPosition::Next4B:
-                return Consume4B(buffer, current);
-            case ArgumentPosition::Next8B:
-                return Consume8B(buffer, current);
-            default:
-                throw MalformedDataError("argument position is reserved for future use, incorrect, "
-                                         "or the parser is out of date");
-            }
-        }
-
         template <std::unsigned_integral T>
         T ExtractUnsigned(std::span<std::uint8_t> buffer, std::size_t &current)
         {
@@ -334,22 +354,6 @@ namespace CBOR
                 return SignedNegative<T>(header, buffer, current);
             }
         }
-
-        std::span<std::uint8_t> ExtractBinary(std::size_t size, std::span<std::uint8_t> buffer, std::size_t &current)
-        {
-            EnsureEnoughSpace(buffer, current, size);
-            std::span<std::uint8_t> result(buffer.data() + current, size);
-            current += size;
-            return result;
-        }
-
-        std::string_view ExtractString(std::size_t size, std::span<std::uint8_t> buffer, std::size_t &current)
-        {
-            EnsureEnoughSpace(buffer, current, size);
-            std::string_view result(reinterpret_cast<const char *>(buffer.data() + current), size);
-            current += size;
-            return result;
-        }
     }
 
     Item::Item(Decoder &decoder)
@@ -479,20 +483,18 @@ namespace CBOR
                                     "use the funcions for those instead");
         }
 
-        std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
-        MajorType major = GetMajorType(header);
+        Decoder::Header header = mDecoder->ExtractHeader();
         mHeaderParsed = true;
-        if (major != MajorType::Binary) {
-            throw TypeMismatchError("binary", ToString(major));
+        if (header.Type != MajorType::Binary) {
+            throw TypeMismatchError("binary", ToString(header.Type));
         }
 
-        if (GetArgumentPosition(header) == ArgumentPosition::Indefinite) {
+        if (header.ArgPosition == ArgumentPosition::Indefinite) {
             throw IndefiniteLengthError();
         }
 
         mDone = true;
-        std::uint64_t arg = ArgumentValue(header, mDecoder->mBuffer, mDecoder->mCurrent);
-        return ExtractBinary(arg, mDecoder->mBuffer, mDecoder->mCurrent);
+        return mDecoder->ExtractBinary(header.Argument);
     }
 
     void Binary::AllowIndefinite()
@@ -510,10 +512,10 @@ namespace CBOR
             return true;
         }
 
-        std::uint8_t header = Read1B(mDecoder->mBuffer, mDecoder->mCurrent);
-        if (GetMajorType(header) == MajorType::Other && GetMinorType(header) == MinorType::Break) {
+        Decoder::Header header = mDecoder->PeekHeader();
+        if (header.Type == MajorType::Other && header.Minor == MinorType::Break) {
             mDone = true;
-            Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
+            mDecoder->ExtractHeader();
         }
         mCheckedDone = true;
         return mDone;
@@ -522,18 +524,16 @@ namespace CBOR
     std::span<std::uint8_t> Binary::Next()
     {
         if (!mHeaderParsed) {
-            std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
+            Decoder::Header header = mDecoder->ExtractHeader();
             mHeaderParsed = true;
-            MajorType major = GetMajorType(header);
-            if (major != MajorType::Binary) {
-                throw TypeMismatchError("binary", ToString(major));
+            if (header.Type != MajorType::Binary) {
+                throw TypeMismatchError("binary", ToString(header.Type));
             }
 
-            if (GetArgumentPosition(header) != ArgumentPosition::Indefinite) {
+            if (header.ArgPosition != ArgumentPosition::Indefinite) {
                 mDone = true;
                 mCheckedDone = true;
-                std::uint64_t arg = ArgumentValue(header, mDecoder->mBuffer, mDecoder->mCurrent);
-                return ExtractBinary(arg, mDecoder->mBuffer, mDecoder->mCurrent);
+                return mDecoder->ExtractBinary(header.Argument);
             }
 
             return std::span<std::uint8_t>();
@@ -548,16 +548,13 @@ namespace CBOR
         }
         mCheckedDone = false;
 
-        std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
-        MajorType major = GetMajorType(header);
-        ArgumentPosition pos = GetArgumentPosition(header);
-        if (major != MajorType::Binary || pos == ArgumentPosition::Indefinite){
-            throw MalformedDataError("an indefinite length string may only contain "
-                                     "definite length strings");
+        Decoder::Header header = mDecoder->ExtractHeader();
+        if (header.Type != MajorType::Binary || header.ArgPosition == ArgumentPosition::Indefinite){
+            throw MalformedDataError("an indefinite length binary may only contain "
+                                     "definite length binaries");
         }
 
-        std::uint64_t arg = ArgumentValue(header, mDecoder->mBuffer, mDecoder->mCurrent);
-        return ExtractBinary(arg, mDecoder->mBuffer, mDecoder->mCurrent);
+        return mDecoder->ExtractBinary(header.Argument);
     }
 
     String::String(Decoder &decoder)
@@ -579,20 +576,18 @@ namespace CBOR
                                     "use the funcions for those instead");
         }
 
-        std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
+        Decoder::Header header = mDecoder->ExtractHeader();
         mHeaderParsed = true;
-        MajorType major = GetMajorType(header);
-        if (major != MajorType::String) {
-            throw TypeMismatchError("string", ToString(major));
+        if (header.Type != MajorType::String) {
+            throw TypeMismatchError("string", ToString(header.Type));
         }
 
-        if (GetArgumentPosition(header) == ArgumentPosition::Indefinite) {
+        if (header.ArgPosition == ArgumentPosition::Indefinite) {
             throw IndefiniteLengthError();
         }
 
         mDone = true;
-        std::uint64_t arg = ArgumentValue(header, mDecoder->mBuffer, mDecoder->mCurrent);
-        return ExtractString(arg, mDecoder->mBuffer, mDecoder->mCurrent);
+        return mDecoder->ExtractString(header.Argument);
     }
 
     void String::AllowIndefinite()
@@ -610,10 +605,10 @@ namespace CBOR
             return true;
         }
 
-        std::uint8_t header = Read1B(mDecoder->mBuffer, mDecoder->mCurrent);
+        std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
         if (GetMajorType(header) == MajorType::Other && GetMinorType(header) == MinorType::Break) {
             mDone = true;
-            Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
+            mDecoder->ExtractHeader();
         }
         mCheckedDone = true;
         return mDone;
@@ -622,18 +617,16 @@ namespace CBOR
     std::string_view String::Next()
     {
         if (!mHeaderParsed) {
-            std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
-            MajorType major = GetMajorType(header);
+            Decoder::Header header = mDecoder->ExtractHeader();
             mHeaderParsed = true;
-            if (major != MajorType::String) {
-                throw TypeMismatchError("string", ToString(major));
+            if (header.Type != MajorType::String) {
+                throw TypeMismatchError("string", ToString(header.Type));
             }
 
-            if (GetArgumentPosition(header) != ArgumentPosition::Indefinite) {
+            if (header.ArgPosition != ArgumentPosition::Indefinite) {
                 mDone = true;
                 mCheckedDone = true;
-                std::uint64_t arg = ArgumentValue(header, mDecoder->mBuffer, mDecoder->mCurrent);
-                return ExtractString(arg, mDecoder->mBuffer, mDecoder->mCurrent);
+                return mDecoder->ExtractString(header.Argument);
             }
 
             return std::string_view();
@@ -648,16 +641,13 @@ namespace CBOR
         }
         mCheckedDone = false;
 
-        std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
-        MajorType major = GetMajorType(header);
-        ArgumentPosition pos = GetArgumentPosition(header);
-        if (major != MajorType::String || pos == ArgumentPosition::Indefinite){
+        Decoder::Header header = mDecoder->ExtractHeader();
+        if (header.Type != MajorType::Binary || header.ArgPosition == ArgumentPosition::Indefinite){
             throw MalformedDataError("an indefinite length string may only contain "
                                      "definite length strings");
         }
 
-        std::uint64_t arg = ArgumentValue(header, mDecoder->mBuffer, mDecoder->mCurrent);
-        return ExtractString(arg, mDecoder->mBuffer, mDecoder->mCurrent);
+        return mDecoder->ExtractString(header.Argument);
     }
 
     Array::Array(Decoder &decoder)
@@ -672,15 +662,14 @@ namespace CBOR
     bool Array::Done()
     {
         if (!mHeaderParsed) {
-            std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
+            Decoder::Header header = mDecoder->ExtractHeader();
             mHeaderParsed = true;
-            if (GetMajorType(header) != MajorType::Array) {
-                throw TypeMismatchError("array", ToString(GetMajorType(header)));
+            if (header.Type != MajorType::Array) {
+                throw TypeMismatchError("array", ToString(header.Type));
             }
 
-            bool indefinite = GetArgumentPosition(header) == ArgumentPosition::Indefinite;
-            mSize = indefinite ? Indefinite
-                               : ArgumentValue(header, mDecoder->mBuffer, mDecoder->mCurrent);
+            bool indefinite = header.ArgPosition == ArgumentPosition::Indefinite;
+            mSize = indefinite ? Indefinite : header.Argument;
 
             if (!mSize) {
                 mDone = true;
@@ -700,10 +689,10 @@ namespace CBOR
             return mDone;
         }
 
-        std::uint8_t header = Read1B(mDecoder->mBuffer, mDecoder->mCurrent);
-        if (GetMajorType(header) == MajorType::Other && GetMinorType(header) == MinorType::Break) {
+        Decoder::Header header = mDecoder->PeekHeader();
+        if (header.Type == MajorType::Other && header.Minor == MinorType::Break) {
             mDone = true;
-            Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
+            mDecoder->ExtractHeader();
         }
         mCheckedDone = true;
         return mDone;
@@ -736,15 +725,14 @@ namespace CBOR
     bool Map::Done()
     {
         if (!mHeaderParsed) {
-            std::uint8_t header = Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
+            Decoder::Header header = mDecoder->ExtractHeader();
             mHeaderParsed = true;
-            if (GetMajorType(header) != MajorType::Map) {
-                throw TypeMismatchError("map", ToString(GetMajorType(header)));
+            if (header.Type != MajorType::Map) {
+                throw TypeMismatchError("map", ToString(header.Type));
             }
 
-            bool indefinite = GetArgumentPosition(header) == ArgumentPosition::Indefinite;
-            mSize = indefinite ? Indefinite
-                               : ArgumentValue(header, mDecoder->mBuffer, mDecoder->mCurrent);
+            bool indefinite = header.ArgPosition == ArgumentPosition::Indefinite;
+            mSize = indefinite ? Indefinite : header.Argument;
 
             if (!mSize) {
                 mDone = true;
@@ -764,10 +752,10 @@ namespace CBOR
             return mDone;
         }
 
-        std::uint8_t header = Read1B(mDecoder->mBuffer, mDecoder->mCurrent);
-        if (GetMajorType(header) == MajorType::Other && GetMinorType(header) == MinorType::Break) {
+        Decoder::Header header = mDecoder->PeekHeader();
+        if (header.Type == MajorType::Other && header.Minor == MinorType::Break) {
             mDone = true;
-            Consume1B(mDecoder->mBuffer, mDecoder->mCurrent);
+            mDecoder->ExtractHeader();
         }
         mCheckedDone = true;
         return mDone;
@@ -789,7 +777,7 @@ namespace CBOR
     }
 
     Decoder::Decoder(std::span<std::uint8_t> buffer)
-        : mCurrent(0), mBuffer(buffer)
+        : mState(State::Initial), mCurrent(0), mBuffer(buffer)
     {}
 
     bool Decoder::Bool()
@@ -921,4 +909,95 @@ namespace CBOR
     {
         return { *this };
     }
+
+    Decoder::Header Decoder::PeekHeader()
+    {
+        EnsureEnoughSpace(mBuffer, mCurrent, 1);
+
+        std::uint8_t rawHeader = mBuffer[mCurrent];
+        Header header {
+            .Type        = MajorType(rawHeader & std::to_underlying(MajorType::TypeMask)),
+            .Minor       = MinorType(rawHeader & std::to_underlying(MinorType::TypeMask)),
+            .ArgPosition = ArgumentPosition(rawHeader & std::to_underlying(ArgumentPosition::PositionMask)),
+            .Argument    = 0,
+        };
+
+        if (std::to_underlying(header.ArgPosition) <= 23) {
+            header.Argument = std::to_underlying(header.ArgPosition);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Next1B) {
+            header.Argument = Read1B(mBuffer, mCurrent + 1);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Next2B) {
+            header.Argument = Read2B(mBuffer, mCurrent + 1);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Next4B) {
+            header.Argument = Read4B(mBuffer, mCurrent + 1);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Next8B) {
+            header.Argument = Read8B(mBuffer, mCurrent + 1);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Indefinite) {
+            // Nothing more needs to happen
+        }
+        else {
+            // bruh, this happends even with the special ending values ...
+            //throw MalformedDataError("value reserved for future use in the input buffer "
+            //                         "(this version may be too old to parse this data)");
+        }
+        return header;
+    }
+
+    Decoder::Header Decoder::ExtractHeader()
+    {
+        EnsureEnoughSpace(mBuffer, mCurrent, 1);
+
+        std::uint8_t rawHeader = mBuffer[mCurrent++];
+        Header header {
+            .Type        = MajorType(rawHeader & std::to_underlying(MajorType::TypeMask)),
+            .Minor       = MinorType(rawHeader & std::to_underlying(MinorType::TypeMask)),
+            .ArgPosition = ArgumentPosition(rawHeader & std::to_underlying(ArgumentPosition::PositionMask)),
+            .Argument    = 0,
+        };
+
+        if (std::to_underlying(header.ArgPosition) <= 23) {
+            header.Argument = std::to_underlying(header.ArgPosition);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Next1B) {
+            header.Argument = Consume1B(mBuffer, mCurrent);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Next2B) {
+            header.Argument = Consume2B(mBuffer, mCurrent);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Next4B) {
+            header.Argument = Consume4B(mBuffer, mCurrent);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Next8B) {
+            header.Argument = Consume8B(mBuffer, mCurrent);
+        }
+        else if (header.ArgPosition == ArgumentPosition::Indefinite) {
+            // Nothing more needs to happen
+        }
+        else {
+            throw MalformedDataError("value reserved for future use in the input buffer "
+                                     "(this version may be too old to parse this data)");
+        }
+        return header;
+    }
+
+    std::span<std::uint8_t> Decoder::ExtractBinary(std::size_t size)
+    {
+        EnsureEnoughSpace(mBuffer, mCurrent, size);
+        std::span<std::uint8_t> result(mBuffer.data() + mCurrent, size);
+        mCurrent += size;
+        return result;
+    }
+
+    std::string_view Decoder::ExtractString(std::size_t size)
+    {
+        EnsureEnoughSpace(mBuffer, mCurrent, size);
+        std::string_view result(reinterpret_cast<const char *>(mBuffer.data() + mCurrent), size);
+        mCurrent += size;
+        return result;
+    }
 }

LibCBOR/Source/Encoder.cpp

@@ -3,6 +3,7 @@
 #include "Core.hpp"
 #include "Utils.hpp"
 
+#include <cmath>
 #include <cstring>
 #include <format>
 #include <utility>

Tests/Main.cpp

@@ -21,7 +21,7 @@ struct SomeStruct
 std::size_t Encode(const SomeStruct &value, std::span<std::uint8_t> buffer)
 {
     CBOR::BasicEncoder enc(buffer);
-    enc.BeginMap(7);
+    enc.BeginIndefiniteMap();
 
     enc.Encode("name");
     enc.Encode(value.name);
@@ -48,10 +48,12 @@ std::size_t Encode(const SomeStruct &value, std::span<std::uint8_t> buffer)
     }
     enc.End();
 
+    enc.End();
+
     return enc.EncodedSize();
 }
 
-SomeStruct Decode1(std::span<std::uint8_t> buffer)
+SomeStruct Decode(std::span<std::uint8_t> buffer)
 {
     SomeStruct result;
 
@@ -90,50 +92,6 @@ SomeStruct Decode1(std::span<std::uint8_t> buffer)
     return result;
 }
 
-SomeStruct Decode2(std::span<std::uint8_t> buffer)
-{
-    SomeStruct result;
-
-    CBOR::Decoder dec(buffer);
-    CBOR::Map object = dec.Map();
-    while (!object.Done()) {
-        CBOR::KeyValue kv = object.Next();
-        std::string_view key = kv.Key().String().Get();
-        CBOR::Item value = kv.Value();
-        if (key == "name") {
-            result.name = value.String().Get();
-        }
-        else if (key == "speed") {
-            result.speed = value.Double();
-        }
-        else if (key == "fov") {
-            result.fov = value.Float();
-        }
-        else if (key == "thing") {
-            result.thing = value.Int8();
-        }
-        else if (key == "slots") {
-            result.slots = value.Int64();
-        }
-        else if (key == "times") {
-            result.times = value.Uint32();
-        }
-        else if (key == "tools") {
-            CBOR::Array tools = value.Array();
-            while(!tools.Done()) {
-                result.tools.push_back("");
-                CBOR::String tool = tools.Next().String();
-                tool.AllowIndefinite();
-                while (!tool.Done()) {
-                    result.tools.back().append(tool.Next());
-                }
-            }
-        }
-    }
-
-    return result;
-}
-
 void Compare(const SomeStruct &s1, const SomeStruct &s2)
 {
     if (s1.name != s2.name) {
@@ -187,11 +145,9 @@ int main()
         std::size_t encodedSize = Encode(expected, buffer);
         std::println("Encoded size: {}", encodedSize);
 
-        SomeStruct result1 = Decode1(std::span<std::uint8_t>(buffer.data(), encodedSize));
-        SomeStruct result2 = Decode2(std::span<std::uint8_t>(buffer.data(), encodedSize));
+        SomeStruct result = Decode(std::span<std::uint8_t>(buffer.data(), encodedSize));
 
-        Compare(expected, result1);
-        Compare(expected, result2);
+        Compare(expected, result);
         std::println("The test has been completed successfully.");
     }
     catch (const std::exception &e) {