Feature/cbor map (#542)

* respect cbor map order

Signed-off-by: Alexey Chernyshov <alexey.n.chernyshov@gmail.com>

Author: Alexey-N-Chernyshov

core/codec/cbor/cbor_encode_stream.cpp

@@ -9,6 +9,15 @@
 #include "common/cmp.hpp"
 
 namespace fc::codec::cbor {
+  CborEncodeStream &CborOrderedMap::operator[](const std::string &key) {
+    // remove old value if present and push new one
+    erase(std::remove_if(
+              begin(), end(), [&key](const auto &p) { return p.first == key; }),
+          end());
+    emplace_back(key, CborEncodeStream{});
+    return back().second;
+  }
+
   CborEncodeStream &CborEncodeStream::operator<<(const Bytes &bytes) {
     return *this << gsl::make_span(bytes);
   }
@@ -100,6 +109,21 @@ namespace fc::codec::cbor {
     return *this;
   }
 
+  CborEncodeStream &CborEncodeStream::operator<<(const CborOrderedMap &map) {
+    addCount(1);
+    writeMap(data_, map.size());
+    const auto count{count_};
+    for (const auto &pair : map) {
+      if (pair.second.count() != 1) {
+        outcome::raise(CborEncodeError::kExpectedMapValueSingle);
+      }
+      *this << common::span::bytestr(common::span::cbytes(pair.first));
+      *this << pair.second;
+    }
+    count_ = count;
+    return *this;
+  }
+
   CborEncodeStream &CborEncodeStream::operator<<(std::nullptr_t) {
     addCount(1);
     writeNull(data_);
@@ -115,6 +139,10 @@ namespace fc::codec::cbor {
     return result;
   }
 
+  size_t CborEncodeStream::count() const {
+    return count_;
+  }
+
   CborEncodeStream CborEncodeStream::list() {
     CborEncodeStream stream;
     stream.is_list_ = true;
@@ -125,6 +153,10 @@ namespace fc::codec::cbor {
     return {};
   }
 
+  CborOrderedMap CborEncodeStream::orderedMap() {
+    return {};
+  }
+
   CborEncodeStream CborEncodeStream::wrap(BytesIn data, size_t count) {
     CborEncodeStream s;
     copy(s.data_, data);

core/codec/cbor/cbor_encode_stream.hpp

@@ -15,6 +15,14 @@
 #include "primitives/cid/cid.hpp"
 
 namespace fc::codec::cbor {
+  class CborEncodeStream;
+
+  /** Cbor map with respect for key order */
+  struct CborOrderedMap
+      : public std::vector<std::pair<std::string, CborEncodeStream>> {
+    CborEncodeStream &operator[](const std::string &key);
+  };
+
   /** Encodes CBOR */
   class CborEncodeStream {
    public:
@@ -98,17 +106,23 @@ namespace fc::codec::cbor {
     CborEncodeStream &operator<<(const BlockParentCbCids &parents);
     /** Encodes list container encode substream */
     CborEncodeStream &operator<<(const CborEncodeStream &other);
-    /** Encodes map container encode substream map */
+    /** Encodes map container encode substream map with canonical order */
     CborEncodeStream &operator<<(
         const std::map<std::string, CborEncodeStream> &map);
+    /** Encodes map container encode substream map with order respect */
+    CborEncodeStream &operator<<(const CborOrderedMap &map);
     /** Encodes null */
     CborEncodeStream &operator<<(std::nullptr_t);
     /** Returns CBOR bytes of encoded elements */
     Bytes data() const;
+    /** Returns the number of elements */
+    size_t count() const;
     /** Creates list container encode substream */
     static CborEncodeStream list();
     /** Creates map container encode substream map */
     static std::map<std::string, CborEncodeStream> map();
+    /** Creates map container encode substream map */
+    static CborOrderedMap orderedMap();
     /** Wraps CBOR bytes */
     static CborEncodeStream wrap(BytesIn data, size_t count);