optimise lzss prefix lookup with custom hashmap

1 files changed, 41 insertions, 30 deletions

diff --git a/tests/tlzss.nim b/tests/tlzss.nim
index ad667e5..39a89c6 100644
--- a/tests/tlzss.nim
+++ b/tests/tlzss.nim
@@ -14,25 +14,36 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-import unittest, sequtils, tables, lists
-import lzss/matchtable, lzss/lzssnode, lzss/lzsschain, lzss/lzssencoder
+import unittest, sequtils, tables, lists, algorithm
+import lzss/matchring, lzss/matchtable, lzss/lzssnode, lzss/lzsschain, lzss/lzssencoder
 
-suite "matchtable":
-  test "matchList":
-    let matchTable = initMatchTable(seq[int], int)
-    check matchTable.matchList(@[0, 1, 2]).len == 0
+suite "matchring":
+  test "items (empty)":
+    var ring = initMatchRing()
+    check toSeq(ring.items).len == 0
+
+  test "addMatch, items (partial)":
+    var ring = initMatchRing()
+    let items = [0, 1, 2]
+    for i in items: ring.addMatch(i)
+    check toSeq(ring.items) == items.reversed()
 
+  test "addMatch, items (rolling)":
+    var ring = initMatchRing()
+    let items = toSeq(0..13)
+    for i in items: ring.addMatch(i)
+    check toSeq(ring.items) == items[^matchLimit..<items.len].reversed()
+
+suite "matchtable":
   test "addMatch":
-    let matchTable = initMatchTable(seq[int], int)
-    matchTable.addMatch(@[0, 1, 2], 42)
-    matchTable.addMatch(@[2, 1, 0], 24)
-    check matchTable.len == 2
-    check matchTable.matchList(@[0, 1, 2]) == [42]
-    check matchTable.matchList(@[2, 1, 0]) == [24]
-    matchTable.addMatch(@[0, 1, 2], 1337)
-    check matchTable.len == 2
-    check matchTable.matchList(@[0, 1, 2]) == [1337, 42]
-    check matchTable.matchList(@[2, 1, 0]) == [24]
+    var matchTable = initMatchTable()
+    matchTable.addMatch([0'u8, 1, 2], 42)
+    matchTable.addMatch([2'u8, 1, 0], 24)
+    check toSeq(matchTable.candidates([0'u8, 1, 2]).items) == [42]
+    check toSeq(matchTable.candidates([2'u8, 1, 0]).items) == [24]
+    matchTable.addMatch([0'u8, 1, 2], 1337)
+    check toSeq(matchTable.candidates([0'u8, 1, 2]).items) == [1337, 42]
+    check toSeq(matchTable.candidates([2'u8, 1, 0]).items) == [24]
 
 suite "lzssnode":
   test "equality":
@@ -54,11 +65,11 @@ suite "lzsschain":
  
 suite "lzssencoder":
   test "commonPrefixLength":
-    check commonPrefixLength([], [], 0, 10) == 0
-    check commonPrefixLength([1'u8, 2], [1'u8, 2, 3], 0, 10) == 2
-    check commonPrefixLength([1'u8, 2], [1'u8, 2, 3], 1, 10) == 2
-    check commonPrefixLength([1'u8, 2, 3], [1'u8, 2, 4], 1, 10) == 2
-    check commonPrefixLength([1'u8, 2, 3, 4], [1'u8, 2, 3, 4], 1, 3) == 3
+    check commonPrefixLength([], [], 10) == 0
+    check commonPrefixLength([1'u8, 2], [1'u8, 2, 3], 10) == 2
+    check commonPrefixLength([1'u8, 2], [1'u8, 2, 3], 10) == 2
+    check commonPrefixLength([1'u8, 2, 3], [1'u8, 2, 4], 10) == 2
+    check commonPrefixLength([1'u8, 2, 3, 4], [1'u8, 2, 3, 4], 3) == 3
 
   test "longestPrefix":
     let buffer = [
@@ -67,22 +78,22 @@ suite "lzssencoder":
       0, 1, 2,
       0, 1, 2, 3, 4]
     var candidatePos = [0, 4, 8]
-    let result = longestPrefix(candidatePos, buffer.toOpenArray(0, 10), buffer.toOpenArray(11, buffer.len - 1))
+    var matchRing = initMatchRing()
+    for pos in candidatePos: matchRing.addMatch(pos)
+    let result = longestPrefix(matchRing, buffer.toOpenArray(0, 10), buffer.toOpenArray(11, buffer.len - 1))
     check result.pos == 4
     check result.length == 4
 
   test "addGroups":
-    let matchTable = initMatchTable(seq[uint8], int)
+    var matchTable = initMatchTable()
     let buffer = toSeq(0'u8..10'u8)
     matchTable.addGroups(buffer, 0, 1)
-    check matchTable.len == 0
     matchTable.addGroups(buffer, 2, 9)
-    check matchTable.len == 5
-    check matchTable.matchList(@[1'u8, 2, 3]).len == 0
-    check matchTable.matchList(@[7'u8, 8, 9]).len == 0
-    check matchTable.matchList(@[2'u8, 3, 4]) == [2]
-    check matchTable.matchList(@[4'u8, 5, 6]) == [4]
-    check matchTable.matchList(@[6'u8, 7, 8]) == [6]
+    check toSeq(matchTable.candidates([1'u8, 2, 3]).items).len == 0
+    check toSeq(matchTable.candidates([7'u8, 8, 9]).items).len == 0
+    check toSeq(matchTable.candidates([2'u8, 3, 4]).items) == [2]
+    check toSeq(matchTable.candidates([4'u8, 5, 6]).items) == [4]
+    check toSeq(matchTable.candidates([6'u8, 7, 8]).items) == [6]
 
   test "lzssEncode":
     let buffer = [0'u8, 1, 2, 3, 4, 5, 0, 1, 2, 3, 0, 1, 4, 5, 0, 5, 5, 0, 5, 5]