Reduce GC on measureText

GMOD · Jul 12, 2022 · 7ea0e45 · 7ea0e45
1 parent db7cb60
commit 7ea0e45
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Showing 3 changed files with 18 additions and 94 deletions.
diff --git a/packages/core/util/Base1DUtils.ts b/packages/core/util/Base1DUtils.ts
@@ -71,8 +71,9 @@ export function pxToBp(self: any, px: number) {
     offsetPx,
     displayedRegions,
     interRegionPaddingWidth,
-    staticBlocks: { blocks },
+    staticBlocks,
   } = self
+  const blocks = staticBlocks.contentBlocks
   const bp = (offsetPx + px) * bpPerPx
   if (bp < 0) {
     const region = displayedRegions[0]
@@ -90,8 +91,7 @@ export function pxToBp(self: any, px: number) {
   }
 
   const interRegionPaddingBp = interRegionPaddingWidth * bpPerPx
-  let firstBlock = true
-  let currStaticBlock = blocks[0]?.regionNumber
+  let currBlock = 0
   for (let i = 0; i < displayedRegions.length; i++) {
     const region = displayedRegions[i]
     const len = region.end - region.start
@@ -112,10 +112,9 @@ export function pxToBp(self: any, px: number) {
 
     // add the interRegionPaddingWidth if the boundary is in the screen e.g. in
     // a static block
-    if (currStaticBlock === i) {
-      bpSoFar += len + (firstBlock ? 0 : interRegionPaddingBp)
-      currStaticBlock++
-      firstBlock = false
+    if (blocks[currBlock]?.regionNumber === i) {
+      bpSoFar += len + interRegionPaddingBp
+      currBlock++
     } else {
       bpSoFar += len
     }

diff --git a/packages/core/util/Base1DViewModel.ts b/packages/core/util/Base1DViewModel.ts
@@ -1,4 +1,4 @@
-import { types, cast, getSnapshot, Instance } from 'mobx-state-tree'
+import { types, cast, Instance } from 'mobx-state-tree'
 import { clamp } from './index'
 import { Feature } from './simpleFeature'
 import { Region, ElementId } from './types/mst'
@@ -63,82 +63,7 @@ const Base1DView = types
     },
 
     pxToBp(px: number) {
-      let bpSoFar = 0
-      const bp = (self.offsetPx + px) * self.bpPerPx
-      const n = self.displayedRegions.length
-      if (bp < 0) {
-        const region = self.displayedRegions[0]
-        const offset = bp
-        const snap = getSnapshot(region)
-        return {
-          ...(snap as Omit<typeof snap, symbol>),
-          oob: true,
-          coord: region.reversed
-            ? Math.floor(region.end - offset) + 1
-            : Math.floor(region.start + offset) + 1,
-          offset,
-          index: 0,
-        }
-      }
-
-      const interRegionPaddingBp = self.interRegionPaddingWidth * self.bpPerPx
-      const minimumBlockBp = self.minimumBlockWidth * self.bpPerPx
-
-      for (let index = 0; index < self.displayedRegions.length; index += 1) {
-        const region = self.displayedRegions[index]
-        const len = region.end - region.start
-        const offset = bp - bpSoFar
-        if (len + bpSoFar > bp && bpSoFar <= bp) {
-          const snap = getSnapshot(region)
-          return {
-            ...(snap as Omit<typeof snap, symbol>),
-            oob: false,
-            offset,
-            coord: region.reversed
-              ? Math.floor(region.end - offset) + 1
-              : Math.floor(region.start + offset) + 1,
-            index,
-          }
-        }
-
-        // add the interRegionPaddingWidth if the boundary is in the screen
-        // e.g. offset>0 && offset<width
-        if (
-          region.end - region.start > minimumBlockBp &&
-          offset / self.bpPerPx > 0 &&
-          offset / self.bpPerPx < this.width
-        ) {
-          bpSoFar += len + interRegionPaddingBp
-        } else {
-          bpSoFar += len
-        }
-      }
-
-      if (bp >= bpSoFar) {
-        const region = self.displayedRegions[n - 1]
-        const len = region.end - region.start
-        const offset = bp - bpSoFar + len
-        const snap = getSnapshot(region)
-        return {
-          ...(snap as Omit<typeof snap, symbol>),
-          oob: true,
-          offset,
-          coord: region.reversed
-            ? Math.floor(region.end - offset) + 1
-            : Math.floor(region.start + offset) + 1,
-          index: n - 1,
-        }
-      }
-      return {
-        coord: 0,
-        index: 0,
-        start: 0,
-        refName: '',
-        oob: true,
-        assemblyName: '',
-        offset: 0,
-        reversed: false,
-      }
+      return pxToBp(self, px)
     },
   }))
   .views(self => ({

diff --git a/packages/core/util/index.ts b/packages/core/util/index.ts
@@ -883,19 +883,19 @@ export const rIC =
       : (cb: Function) => setTimeout(() => cb(), 1)
     : (cb: Function) => cb()
 
+// prettier-ignore
+const widths = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.2796875,0.2765625,0.3546875,0.5546875,0.5546875,0.8890625,0.665625,0.190625,0.3328125,0.3328125,0.3890625,0.5828125,0.2765625,0.3328125,0.2765625,0.3015625,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.2765625,0.2765625,0.584375,0.5828125,0.584375,0.5546875,1.0140625,0.665625,0.665625,0.721875,0.721875,0.665625,0.609375,0.7765625,0.721875,0.2765625,0.5,0.665625,0.5546875,0.8328125,0.721875,0.7765625,0.665625,0.7765625,0.721875,0.665625,0.609375,0.721875,0.665625,0.94375,0.665625,0.665625,0.609375,0.2765625,0.3546875,0.2765625,0.4765625,0.5546875,0.3328125,0.5546875,0.5546875,0.5,0.5546875,0.5546875,0.2765625,0.5546875,0.5546875,0.221875,0.240625,0.5,0.221875,0.8328125,0.5546875,0.5546875,0.5546875,0.5546875,0.3328125,0.5,0.2765625,0.5546875,0.5,0.721875,0.5,0.5,0.5,0.3546875,0.259375,0.353125,0.5890625]
+
 // xref https://gist.github.com/tophtucker/62f93a4658387bb61e4510c37e2e97cf
 export function measureText(str: unknown, fontSize = 10) {
-  // prettier-ignore
-  const widths = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.2796875,0.2765625,0.3546875,0.5546875,0.5546875,0.8890625,0.665625,0.190625,0.3328125,0.3328125,0.3890625,0.5828125,0.2765625,0.3328125,0.2765625,0.3015625,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.5546875,0.2765625,0.2765625,0.584375,0.5828125,0.584375,0.5546875,1.0140625,0.665625,0.665625,0.721875,0.721875,0.665625,0.609375,0.7765625,0.721875,0.2765625,0.5,0.665625,0.5546875,0.8328125,0.721875,0.7765625,0.665625,0.7765625,0.721875,0.665625,0.609375,0.721875,0.665625,0.94375,0.665625,0.665625,0.609375,0.2765625,0.3546875,0.2765625,0.4765625,0.5546875,0.3328125,0.5546875,0.5546875,0.5,0.5546875,0.5546875,0.2765625,0.5546875,0.5546875,0.221875,0.240625,0.5,0.221875,0.8328125,0.5546875,0.5546875,0.5546875,0.5546875,0.3328125,0.5,0.2765625,0.5546875,0.5,0.721875,0.5,0.5,0.5,0.3546875,0.259375,0.353125,0.5890625]
   const avg = 0.5279276315789471
-  return (
-    String(str)
-      .split('')
-      .map(c =>
-        c.charCodeAt(0) < widths.length ? widths[c.charCodeAt(0)] : avg,
-      )
-      .reduce((cur, acc) => acc + cur, 0) * fontSize
-  )
+  const s = String(str)
+  let total = 0
+  for (let i = 0; i < s.length; i++) {
+    const code = s.charCodeAt(i)
+    total += widths[code] ?? avg
+  }
+  return total * fontSize
 }
 
 export const defaultStarts = ['ATG']