From fcadfc4797287ced4905bc94c943b47a83b8a862 Mon Sep 17 00:00:00 2001
From: Andre Staltz <andre@staltz.com>
Date: Tue, 29 Mar 2022 15:42:36 +0300
Subject: [PATCH 1/3] use binary search to get seq from offset

---
 index.js | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/index.js b/index.js
index 3fc1c00..cd2fafb 100644
--- a/index.js
+++ b/index.js
@@ -305,6 +305,21 @@ module.exports = function (log, indexesPath) {
     }
   }
 
+  function getSeqFromOffset(offset) {
+    if (offset === -1) return 0
+    const { tarr, count } = indexes['seq']
+    let low = 0
+    let high = count - 1
+    let mid = 0
+    while (low <= high) {
+      mid = Math.floor((low + high) * 0.5)
+      if (tarr[mid] < offset) low = mid + 1
+      else if (tarr[mid] > offset) high = mid - 1
+      else return mid
+    }
+    throw new Error(`getSeqFromOffset: offset ${offset} not found`)
+  }
+
   const undefinedBipf = bipf.allocAndEncode(undefined)
 
   function checkEqual(opData, buffer) {
@@ -483,17 +498,8 @@ module.exports = function (log, indexesPath) {
       index.count = 0
     }
 
-    // find the next possible seq
-    let seq = 0
-    if (index.offset !== -1) {
-      const { tarr } = indexes['seq']
-      const indexOffset = index.offset
-      for (const len = tarr.length; seq < len; ++seq)
-        if (tarr[seq] === indexOffset) {
-          seq++
-          break
-        }
-    }
+    // Find the next possible seq
+    let seq = index.offset === -1 ? 0 : getSeqFromOffset(index.offset) + 1
 
     let updatedSeqIndex = false
     let updatedTimestampIndex = false
@@ -1510,11 +1516,8 @@ module.exports = function (log, indexesPath) {
     if (offset === 0 || offset === -1) {
       prevOffset = -1
     } else {
-      const { tarr } = indexes['seq']
-      for (const len = tarr.length; seq < len; ++seq) {
-        if (tarr[seq] === offset) break
-        else prevOffset = tarr[seq]
-      }
+      seq = getSeqFromOffset(offset)
+      prevOffset = indexes['seq'].tarr[seq - 1]
     }
 
     if (prevOffset === 0 && seq === indexes['seq'].tarr.length) {

From 020e69923e9051cfafa1297875f70a1269c56df0 Mon Sep 17 00:00:00 2001
From: Andre Staltz <andre@staltz.com>
Date: Tue, 29 Mar 2022 16:43:14 +0300
Subject: [PATCH 2/3] use bsb.eq in getSeqFromOffset

---
 index.js | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/index.js b/index.js
index cd2fafb..d04600d 100644
--- a/index.js
+++ b/index.js
@@ -308,16 +308,9 @@ module.exports = function (log, indexesPath) {
   function getSeqFromOffset(offset) {
     if (offset === -1) return 0
     const { tarr, count } = indexes['seq']
-    let low = 0
-    let high = count - 1
-    let mid = 0
-    while (low <= high) {
-      mid = Math.floor((low + high) * 0.5)
-      if (tarr[mid] < offset) low = mid + 1
-      else if (tarr[mid] > offset) high = mid - 1
-      else return mid
-    }
-    throw new Error(`getSeqFromOffset: offset ${offset} not found`)
+    const seq = bsb.eq(tarr, offset, 0, count - 1)
+    if (seq < 0) throw new Error(`getSeqFromOffset(${offset}) not found`)
+    return seq
   }
 
   const undefinedBipf = bipf.allocAndEncode(undefined)

From bcba09eff01981fa8e384883adfafcdbbbd6580f Mon Sep 17 00:00:00 2001
From: Andre Staltz <andre@staltz.com>
Date: Tue, 29 Mar 2022 16:44:02 +0300
Subject: [PATCH 3/3] use seq index.count instead of index.tarr.length

---
 index.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index d04600d..1a6b2cb 100644
--- a/index.js
+++ b/index.js
@@ -841,8 +841,8 @@ module.exports = function (log, indexesPath) {
     const seqs = []
     opOffsets.sort((x, y) => x - y)
     const opOffsetsLen = opOffsets.length
-    const { tarr } = indexes['seq']
-    for (let seq = 0, len = tarr.length; seq < len; ++seq) {
+    const { tarr, count } = indexes['seq']
+    for (let seq = 0; seq < count; ++seq) {
       if (bsb.eq(opOffsets, tarr[seq]) !== -1) seqs.push(seq)
       if (seqs.length === opOffsetsLen) break
     }
@@ -1513,7 +1513,7 @@ module.exports = function (log, indexesPath) {
       prevOffset = indexes['seq'].tarr[seq - 1]
     }
 
-    if (prevOffset === 0 && seq === indexes['seq'].tarr.length) {
+    if (prevOffset === 0 && seq === indexes['seq'].count) {
       // not found
       seq = 1
     }