Resolve "TransactionDocument: replace Vec fields by SmallVec"

Closes #197

lib/dubp/user-docs/src/documents/transaction/v10.rs

@@ -27,6 +27,7 @@ use durs_common_tools::{fatal_error, UsizeSer32};
 use pest::iterators::Pair;
 use pest::iterators::Pairs;
 use pest::Parser;
+use smallvec::SmallVec;
 use std::str::FromStr;
 use unwrap::unwrap;
 
@@ -288,17 +289,17 @@ pub struct TransactionDocumentV10 {
     /// Locktime
     locktime: u64,
     /// Document issuers.
-    issuers: Vec<PubKey>,
+    issuers: SmallVec<[PubKey; 4]>,
     /// Transaction inputs.
-    inputs: Vec<TransactionInputV10>,
+    inputs: SmallVec<[TransactionInputV10; 32]>,
     /// Inputs unlocks.
-    unlocks: Vec<TransactionInputUnlocksV10>,
+    unlocks: SmallVec<[TransactionInputUnlocksV10; 32]>,
     /// Transaction outputs.
-    outputs: Vec<TransactionOutputV10>,
+    outputs: SmallVec<[TransactionOutputV10; 8]>,
     /// Transaction comment
     comment: String,
     /// Document signatures.
-    signatures: Vec<Sig>,
+    signatures: SmallVec<[Sig; 4]>,
     /// Transaction hash
     hash: Option<Hash>,
 }
@@ -407,12 +408,12 @@ impl TransactionDocumentV10 {
         let mut currency = "";
         let mut blockstamp = Blockstamp::default();
         let mut locktime = 0;
-        let mut issuers = Vec::new();
-        let mut inputs = Vec::new();
-        let mut unlocks = Vec::new();
-        let mut outputs = Vec::new();
+        let mut issuers = SmallVec::<[PubKey; 4]>::new();
+        let mut inputs = SmallVec::new();
+        let mut unlocks = SmallVec::new();
+        let mut outputs = SmallVec::new();
         let mut comment = "";
-        let mut sigs = Vec::new();
+        let mut sigs = SmallVec::<[Sig; 4]>::new();
 
         for field in pair.into_inner() {
             match field.as_rule() {
@@ -482,11 +483,11 @@ impl Document for TransactionDocumentV10 {
         self.blockstamp
     }
 
-    fn issuers(&self) -> &Vec<PubKey> {
+    fn issuers(&self) -> &SmallVec<[PubKey; 4]> {
         &self.issuers
     }
 
-    fn signatures(&self) -> &Vec<Sig> {
+    fn signatures(&self) -> &SmallVec<[Sig; 4]> {
         &self.signatures
     }
 
@@ -598,12 +599,12 @@ impl<'a> TransactionDocumentV10Builder<'a> {
             currency: self.currency.to_string(),
             blockstamp: *self.blockstamp,
             locktime: *self.locktime,
-            issuers: self.issuers.to_vec(),
-            inputs: self.inputs.to_vec(),
-            unlocks: self.unlocks.to_vec(),
-            outputs: self.outputs.to_vec(),
+            issuers: SmallVec::from_slice(self.issuers),
+            inputs: SmallVec::from_slice(self.inputs),
+            unlocks: SmallVec::from(self.unlocks),
+            outputs: SmallVec::from(self.outputs),
             comment: String::from(self.comment),
-            signatures,
+            signatures: SmallVec::from_vec(signatures),
             hash: self.hash,
         }
     }