0841ce2 · elk · git.iko.soy

git.iko.soy/elk

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Add cache for M^i

0841ce2Christian Widera13 years ago

libraries/Native/Array.js+10−9

compare with master

unifiedsplit

@@ -34,20 +34,15 @@ Elm.Native.Array.make = function(elm) {

34 }

36 function unsafeGet(i, array) {

37− var slotSize = Math.pow(M, array.height);

37+ for (var x = array.height; x > 0; x--) {

38−

39− while (true) {

40− var slot = Math.floor(i / slotSize);

38+ var slot = Math.floor(i / cache[x]);

41 while (array.lengths[slot] <= i) {

39 while (array.lengths[slot] <= i) {

42 slot++;

40 slot++;

43 }

41 }

44 i -= slot > 0 ? array.lengths[slot - 1] : 0;

42 i -= slot > 0 ? array.lengths[slot - 1] : 0;

45 array = array.table[slot];

43 array = array.table[slot];

46− if (array.height == 0) {

47− return array.table[i];

48− }

49− slotSize /= M;

50 }

44 }

45+ return array.table[i];

51 }

46 }

53 // Sets the value at the index i. Only the nodes leading to i will get

48 // Sets the value at the index i. Only the nodes leading to i will get

@@ -537,10 +532,16 @@ Elm.Native.Array.make = function(elm) {

537 }

532 }

538 }

533 }

539

534

535+ // Cache for Math.pow(M, i)

536+ cache = new Array(10);

537+ for (var i = 0; i < cache.length; i++) {

538+ cache[i] = Math.pow(M, i);

539+ }

540+

540 // Calculates in which slot of "table" the item probably is, then

541 // Calculates in which slot of "table" the item probably is, then

541 // find the exact slot via forward searching in "lengths". Returns the index.

542 // find the exact slot via forward searching in "lengths". Returns the index.

542 function getSlot(i, a) {

543 function getSlot(i, a) {

543− var slot = Math.floor(i / (Math.pow(M, a.height)));

544+ var slot = Math.floor(i / cache[a.height]);

544 while (a.lengths[slot] <= i) {

545 while (a.lengths[slot] <= i) {

545 slot++

546 slot++

546 }

547 }