Allow skipping value for compact proof

trie-db/src/lib.rs

@@ -22,14 +22,16 @@ extern crate alloc;
 mod rstd {
 	pub use std::{borrow, boxed, cmp, convert, fmt, hash, iter, marker, mem, ops, rc, result, vec};
 	pub use std::collections::VecDeque;
+	pub use std::collections::BTreeMap;
 	pub use std::error::Error;
 }
 
 #[cfg(not(feature = "std"))]
 mod rstd {
-	pub use core::{borrow, convert, cmp, iter, fmt, hash, marker, mem, ops, result};
-	pub use alloc::{boxed, rc, vec};
+	pub use core::{convert, cmp, iter, fmt, hash, marker, mem, ops, result};
+	pub use alloc::{borrow, boxed, rc, vec};
 	pub use alloc::collections::VecDeque;
+	pub use alloc::collections::btree_map::BTreeMap;
 	pub trait Error {}
 	impl<T> Error for T {}
 }
@@ -71,7 +73,11 @@ pub use crate::node_codec::{NodeCodec, Partial};
 pub use crate::iter_build::{trie_visit, ProcessEncodedNode,
 	 TrieBuilder, TrieRoot, TrieRootUnhashed};
 pub use crate::iterator::TrieDBNodeIterator;
-pub use crate::trie_codec::{decode_compact, decode_compact_from_iter, encode_compact};
+pub use crate::trie_codec::{encode_compact,
+	decode_compact, decode_compact_from_iter, decode_compact_with_known_values,
+	decode_compact_for_encoded_skipped_values, encode_compact_skip_all_values,
+	LazyFetcher, compact_conditions, encode_compact_skip_conditional,
+	encode_compact_skip_conditional_with_key};
 
 #[cfg(feature = "std")]
 pub use crate::iter_build::TrieRootPrint;

trie-db/src/nibble/leftnibbleslice.rs

@@ -92,6 +92,15 @@ impl<'a> LeftNibbleSlice<'a> {
 		// If common nibble prefix is the same, finally compare lengths.
 		self.len().cmp(&other.len())
 	}
+
+	/// If nibble are aligned (true for any value), return slice to the key.
+	pub fn as_slice(&self) -> Option<&'a [u8]> {
+		if self.len % NIBBLE_PER_BYTE == 0 {
+			Some(&self.bytes[..self.len / NIBBLE_PER_BYTE])
+		} else {
+			None
+		}
+	}
 }
 
 impl<'a> PartialEq for LeftNibbleSlice<'a> {
@@ -226,4 +235,4 @@ mod tests {
 			Ordering::Equal
 		);
 	}
-}
+}

trie-db/src/node.rs

@@ -95,6 +95,14 @@ impl NibbleSlicePlan {
 		}
 	}
 
+	/// A empty nibbleslice.
+	pub fn empty() -> Self {
+		NibbleSlicePlan {
+			bytes: 0..0,
+			offset: 0,
+		}
+	}
+
 	/// Returns the nibble length of the slice.
 	pub fn len(&self) -> usize {
 		(self.bytes.end - self.bytes.start) * nibble_ops::NIBBLE_PER_BYTE - self.offset