diff options
| author | mo khan <mo@mokhan.ca> | 2025-07-22 17:35:49 -0600 |
|---|---|---|
| committer | mo khan <mo@mokhan.ca> | 2025-07-22 17:35:49 -0600 |
| commit | 20ef0d92694465ac86b550df139e8366a0a2b4fa (patch) | |
| tree | 3f14589e1ce6eb9306a3af31c3a1f9e1af5ed637 /vendor/github.com/charmbracelet/x/cellbuf/hashmap.go | |
| parent | 44e0d272c040cdc53a98b9f1dc58ae7da67752e6 (diff) | |
feat: connect to spicedb
Diffstat (limited to 'vendor/github.com/charmbracelet/x/cellbuf/hashmap.go')
| -rw-r--r-- | vendor/github.com/charmbracelet/x/cellbuf/hashmap.go | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/vendor/github.com/charmbracelet/x/cellbuf/hashmap.go b/vendor/github.com/charmbracelet/x/cellbuf/hashmap.go new file mode 100644 index 0000000..0d25b54 --- /dev/null +++ b/vendor/github.com/charmbracelet/x/cellbuf/hashmap.go @@ -0,0 +1,301 @@ +package cellbuf + +import ( + "github.com/charmbracelet/x/ansi" +) + +// hash returns the hash value of a [Line]. +func hash(l Line) (h uint64) { + for _, c := range l { + var r rune + if c == nil { + r = ansi.SP + } else { + r = c.Rune + } + h += (h << 5) + uint64(r) + } + return +} + +// hashmap represents a single [Line] hash. +type hashmap struct { + value uint64 + oldcount, newcount int + oldindex, newindex int +} + +// The value used to indicate lines created by insertions and scrolls. +const newIndex = -1 + +// updateHashmap updates the hashmap with the new hash value. +func (s *Screen) updateHashmap() { + height := s.newbuf.Height() + if len(s.oldhash) >= height && len(s.newhash) >= height { + // rehash changed lines + for i := 0; i < height; i++ { + _, ok := s.touch[i] + if ok { + s.oldhash[i] = hash(s.curbuf.Line(i)) + s.newhash[i] = hash(s.newbuf.Line(i)) + } + } + } else { + // rehash all + if len(s.oldhash) != height { + s.oldhash = make([]uint64, height) + } + if len(s.newhash) != height { + s.newhash = make([]uint64, height) + } + for i := 0; i < height; i++ { + s.oldhash[i] = hash(s.curbuf.Line(i)) + s.newhash[i] = hash(s.newbuf.Line(i)) + } + } + + s.hashtab = make([]hashmap, height*2) + for i := 0; i < height; i++ { + hashval := s.oldhash[i] + + // Find matching hash or empty slot + idx := 0 + for idx < len(s.hashtab) && s.hashtab[idx].value != 0 { + if s.hashtab[idx].value == hashval { + break + } + idx++ + } + + s.hashtab[idx].value = hashval // in case this is a new hash + s.hashtab[idx].oldcount++ + s.hashtab[idx].oldindex = i + } + for i := 0; i < height; i++ { + hashval := s.newhash[i] + + // Find matching hash or empty slot + idx := 0 + for idx < len(s.hashtab) && s.hashtab[idx].value != 0 { + if s.hashtab[idx].value == hashval { + break + } + idx++ + } + + s.hashtab[idx].value = hashval // in case this is a new hash + s.hashtab[idx].newcount++ + s.hashtab[idx].newindex = i + + s.oldnum[i] = newIndex // init old indices slice + } + + // Mark line pair corresponding to unique hash pairs. + for i := 0; i < len(s.hashtab) && s.hashtab[i].value != 0; i++ { + hsp := &s.hashtab[i] + if hsp.oldcount == 1 && hsp.newcount == 1 && hsp.oldindex != hsp.newindex { + s.oldnum[hsp.newindex] = hsp.oldindex + } + } + + s.growHunks() + + // Eliminate bad or impossible shifts. This includes removing those hunks + // which could not grow because of conflicts, as well those which are to be + // moved too far, they are likely to destroy more than carry. + for i := 0; i < height; { + var start, shift, size int + for i < height && s.oldnum[i] == newIndex { + i++ + } + if i >= height { + break + } + start = i + shift = s.oldnum[i] - i + i++ + for i < height && s.oldnum[i] != newIndex && s.oldnum[i]-i == shift { + i++ + } + size = i - start + if size < 3 || size+min(size/8, 2) < abs(shift) { + for start < i { + s.oldnum[start] = newIndex + start++ + } + } + } + + // After clearing invalid hunks, try grow the rest. + s.growHunks() +} + +// scrollOldhash +func (s *Screen) scrollOldhash(n, top, bot int) { + if len(s.oldhash) == 0 { + return + } + + size := bot - top + 1 - abs(n) + if n > 0 { + // Move existing hashes up + copy(s.oldhash[top:], s.oldhash[top+n:top+n+size]) + // Recalculate hashes for newly shifted-in lines + for i := bot; i > bot-n; i-- { + s.oldhash[i] = hash(s.curbuf.Line(i)) + } + } else { + // Move existing hashes down + copy(s.oldhash[top-n:], s.oldhash[top:top+size]) + // Recalculate hashes for newly shifted-in lines + for i := top; i < top-n; i++ { + s.oldhash[i] = hash(s.curbuf.Line(i)) + } + } +} + +func (s *Screen) growHunks() { + var ( + backLimit int // limits for cells to fill + backRefLimit int // limit for references + i int + nextHunk int + ) + + height := s.newbuf.Height() + for i < height && s.oldnum[i] == newIndex { + i++ + } + for ; i < height; i = nextHunk { + var ( + forwardLimit int + forwardRefLimit int + end int + start = i + shift = s.oldnum[i] - i + ) + + // get forward limit + i = start + 1 + for i < height && + s.oldnum[i] != newIndex && + s.oldnum[i]-i == shift { + i++ + } + + end = i + for i < height && s.oldnum[i] == newIndex { + i++ + } + + nextHunk = i + forwardLimit = i + if i >= height || s.oldnum[i] >= i { + forwardRefLimit = i + } else { + forwardRefLimit = s.oldnum[i] + } + + i = start - 1 + + // grow back + if shift < 0 { + backLimit = backRefLimit + (-shift) + } + for i >= backLimit { + if s.newhash[i] == s.oldhash[i+shift] || + s.costEffective(i+shift, i, shift < 0) { + s.oldnum[i] = i + shift + } else { + break + } + i-- + } + + i = end + // grow forward + if shift > 0 { + forwardLimit = forwardRefLimit - shift + } + for i < forwardLimit { + if s.newhash[i] == s.oldhash[i+shift] || + s.costEffective(i+shift, i, shift > 0) { + s.oldnum[i] = i + shift + } else { + break + } + i++ + } + + backLimit = i + backRefLimit = backLimit + if shift > 0 { + backRefLimit += shift + } + } +} + +// costEffective returns true if the cost of moving line 'from' to line 'to' seems to be +// cost effective. 'blank' indicates whether the line 'to' would become blank. +func (s *Screen) costEffective(from, to int, blank bool) bool { + if from == to { + return false + } + + newFrom := s.oldnum[from] + if newFrom == newIndex { + newFrom = from + } + + // On the left side of >= is the cost before moving. On the right side -- + // cost after moving. + + // Calculate costs before moving. + var costBeforeMove int + if blank { + // Cost of updating blank line at destination. + costBeforeMove = s.updateCostBlank(s.newbuf.Line(to)) + } else { + // Cost of updating exiting line at destination. + costBeforeMove = s.updateCost(s.curbuf.Line(to), s.newbuf.Line(to)) + } + + // Add cost of updating source line + costBeforeMove += s.updateCost(s.curbuf.Line(newFrom), s.newbuf.Line(from)) + + // Calculate costs after moving. + var costAfterMove int + if newFrom == from { + // Source becomes blank after move + costAfterMove = s.updateCostBlank(s.newbuf.Line(from)) + } else { + // Source gets updated from another line + costAfterMove = s.updateCost(s.curbuf.Line(newFrom), s.newbuf.Line(from)) + } + + // Add cost of moving source line to destination + costAfterMove += s.updateCost(s.curbuf.Line(from), s.newbuf.Line(to)) + + // Return true if moving is cost effective (costs less or equal) + return costBeforeMove >= costAfterMove +} + +func (s *Screen) updateCost(from, to Line) (cost int) { + var fidx, tidx int + for i := s.newbuf.Width() - 1; i > 0; i, fidx, tidx = i-1, fidx+1, tidx+1 { + if !cellEqual(from.At(fidx), to.At(tidx)) { + cost++ + } + } + return +} + +func (s *Screen) updateCostBlank(to Line) (cost int) { + var tidx int + for i := s.newbuf.Width() - 1; i > 0; i, tidx = i-1, tidx+1 { + if !cellEqual(nil, to.At(tidx)) { + cost++ + } + } + return +} |
