diff options
Diffstat (limited to 'lib/pure/ropes.nim')
| -rw-r--r-- | lib/pure/ropes.nim | 170 |
1 files changed, 94 insertions, 76 deletions
diff --git a/lib/pure/ropes.nim b/lib/pure/ropes.nim index 995dff2aa..5c7fedfe3 100644 --- a/lib/pure/ropes.nim +++ b/lib/pure/ropes.nim @@ -43,7 +43,7 @@ proc isConc(r: Rope): bool {.inline.} = return isNil(r.data) # Note that the left and right pointers are not needed for leafs. # Leaves have relatively high memory overhead (~30 bytes on a 32 # bit machine) and we produce many of them. This is why we cache and -# share leafs accross different rope trees. +# share leafs across different rope trees. # To cache them they are inserted in another tree, a splay tree for best # performance. But for the caching tree we use the leaf's left and right # pointers. @@ -52,9 +52,9 @@ proc len*(a: Rope): int {.rtl, extern: "nro$1".} = ## the rope's length if a == nil: result = 0 else: result = a.length - + proc newRope(): Rope = new(result) -proc newRope(data: string): Rope = +proc newRope(data: string): Rope = new(result) result.length = len(data) result.data = data @@ -65,18 +65,18 @@ var when countCacheMisses: var misses, hits: int - -proc splay(s: string, tree: Rope, cmpres: var int): Rope = + +proc splay(s: string, tree: Rope, cmpres: var int): Rope = var c: int var t = tree N.left = nil N.right = nil # reset to nil var le = N var r = N - while true: + while true: c = cmp(s, t.data) - if c < 0: - if (t.left != nil) and (s < t.left.data): + if c < 0: + if (t.left != nil) and (s < t.left.data): var y = t.left t.left = y.right y.right = t @@ -85,8 +85,8 @@ proc splay(s: string, tree: Rope, cmpres: var int): Rope = r.left = t r = t t = t.left - elif c > 0: - if (t.right != nil) and (s > t.right.data): + elif c > 0: + if (t.right != nil) and (s > t.right.data): var y = t.right t.right = y.left y.left = t @@ -95,8 +95,8 @@ proc splay(s: string, tree: Rope, cmpres: var int): Rope = le.right = t le = t t = t.right - else: - break + else: + break cmpres = c le.right = t.left r.left = t.right @@ -104,50 +104,50 @@ proc splay(s: string, tree: Rope, cmpres: var int): Rope = t.right = N.left result = t -proc insertInCache(s: string, tree: Rope): Rope = +proc insertInCache(s: string, tree: Rope): Rope = var t = tree - if t == nil: + if t == nil: result = newRope(s) when countCacheMisses: inc(misses) return var cmp: int t = splay(s, t, cmp) - if cmp == 0: + if cmp == 0: # We get here if it's already in the Tree # Don't add it again result = t when countCacheMisses: inc(hits) - else: + else: when countCacheMisses: inc(misses) result = newRope(s) - if cmp < 0: + if cmp < 0: result.left = t.left result.right = t t.left = nil - else: + else: # i > t.item: result.right = t.right result.left = t t.right = nil proc rope*(s: string): Rope {.rtl, extern: "nro$1Str".} = - ## Converts a string to a rope. - if s.len == 0: + ## Converts a string to a rope. + if s.len == 0: result = nil - elif cacheEnabled: + elif cacheEnabled: result = insertInCache(s, cache) cache = result - else: + else: result = newRope(s) - -proc rope*(i: BiggestInt): Rope {.rtl, extern: "nro$1BiggestInt".} = - ## Converts an int to a rope. + +proc rope*(i: BiggestInt): Rope {.rtl, extern: "nro$1BiggestInt".} = + ## Converts an int to a rope. result = rope($i) proc rope*(f: BiggestFloat): Rope {.rtl, extern: "nro$1BiggestFloat".} = - ## Converts a float to a rope. + ## Converts a float to a rope. result = rope($f) - + proc enableCache*() {.rtl, extern: "nro$1".} = ## Enables the caching of leaves. This reduces the memory footprint at ## the cost of runtime efficiency. @@ -160,9 +160,9 @@ proc disableCache*() {.rtl, extern: "nro$1".} = proc `&`*(a, b: Rope): Rope {.rtl, extern: "nroConcRopeRope".} = ## the concatenation operator for ropes. - if a == nil: + if a == nil: result = b - elif b == nil: + elif b == nil: result = a else: result = newRope() @@ -177,16 +177,16 @@ proc `&`*(a, b: Rope): Rope {.rtl, extern: "nroConcRopeRope".} = else: result.left = a result.right = b - -proc `&`*(a: Rope, b: string): Rope {.rtl, extern: "nroConcRopeStr".} = + +proc `&`*(a: Rope, b: string): Rope {.rtl, extern: "nroConcRopeStr".} = ## the concatenation operator for ropes. result = a & rope(b) - -proc `&`*(a: string, b: Rope): Rope {.rtl, extern: "nroConcStrRope".} = + +proc `&`*(a: string, b: Rope): Rope {.rtl, extern: "nroConcStrRope".} = ## the concatenation operator for ropes. result = rope(a) & b - -proc `&`*(a: openArray[Rope]): Rope {.rtl, extern: "nroConcOpenArray".} = + +proc `&`*(a: openArray[Rope]): Rope {.rtl, extern: "nroConcOpenArray".} = ## the concatenation operator for an openarray of ropes. for i in countup(0, high(a)): result = result & a[i] @@ -219,7 +219,7 @@ iterator leaves*(r: Rope): string = ## iterates over any leaf string in the rope `r`. if r != nil: var stack = @[r] - while stack.len > 0: + while stack.len > 0: var it = stack.pop while isConc(it): stack.add(it.right) @@ -227,7 +227,7 @@ iterator leaves*(r: Rope): string = assert(it != nil) assert(it.data != nil) yield it.data - + iterator items*(r: Rope): char = ## iterates over any character in the rope `r`. for s in leaves(r): @@ -237,7 +237,7 @@ proc write*(f: File, r: Rope) {.rtl, extern: "nro$1".} = ## writes a rope to a file. for s in leaves(r): write(f, s) -proc `$`*(r: Rope): string {.rtl, extern: "nroToString".}= +proc `$`*(r: Rope): string {.rtl, extern: "nroToString".}= ## converts a rope back to a string. result = newString(r.len) setLen(result, 0) @@ -251,25 +251,25 @@ when false: new(result) result.length = -idx - proc compileFrmt(frmt: string): Rope = + proc compileFrmt(frmt: string): Rope = var i = 0 var length = len(frmt) result = nil var num = 0 - while i < length: - if frmt[i] == '$': + while i < length: + if frmt[i] == '$': inc(i) case frmt[i] - of '$': + of '$': add(result, "$") inc(i) - of '#': + of '#': inc(i) add(result, compiledArg(num+1)) inc(num) - of '0'..'9': + of '0'..'9': var j = 0 - while true: + while true: j = j * 10 + ord(frmt[i]) - ord('0') inc(i) if frmt[i] notin {'0'..'9'}: break @@ -285,13 +285,13 @@ when false: add(s, compiledArg(j)) else: raise newException(EInvalidValue, "invalid format string") var start = i - while i < length: + while i < length: if frmt[i] != '$': inc(i) - else: break - if i - 1 >= start: + else: break + if i - 1 >= start: add(result, substr(frmt, start, i-1)) - -proc `%`*(frmt: string, args: openArray[Rope]): Rope {. + +proc `%`*(frmt: string, args: openArray[Rope]): Rope {. rtl, extern: "nroFormat".} = ## `%` substitution operator for ropes. Does not support the ``$identifier`` ## nor ``${identifier}`` notations. @@ -299,23 +299,23 @@ proc `%`*(frmt: string, args: openArray[Rope]): Rope {. var length = len(frmt) result = nil var num = 0 - while i < length: - if frmt[i] == '$': + while i < length: + if frmt[i] == '$': inc(i) case frmt[i] - of '$': + of '$': add(result, "$") inc(i) - of '#': + of '#': inc(i) add(result, args[num]) inc(num) - of '0'..'9': + of '0'..'9': var j = 0 - while true: + while true: j = j * 10 + ord(frmt[i]) - ord('0') inc(i) - if frmt[i] notin {'0'..'9'}: break + if frmt[i] notin {'0'..'9'}: break add(result, args[j-1]) of '{': inc(i) @@ -325,13 +325,14 @@ proc `%`*(frmt: string, args: openArray[Rope]): Rope {. inc(i) if frmt[i] == '}': inc(i) else: raise newException(ValueError, "invalid format string") + add(result, args[j-1]) else: raise newException(ValueError, "invalid format string") var start = i - while i < length: + while i < length: if frmt[i] != '$': inc(i) - else: break - if i - 1 >= start: + else: break + if i - 1 >= start: add(result, substr(frmt, start, i - 1)) proc addf*(c: var Rope, frmt: string, args: openArray[Rope]) {. @@ -339,29 +340,46 @@ proc addf*(c: var Rope, frmt: string, args: openArray[Rope]) {. ## shortcut for ``add(c, frmt % args)``. add(c, frmt % args) +const + bufSize = 1024 # 1 KB is reasonable + proc equalsFile*(r: Rope, f: File): bool {.rtl, extern: "nro$1File".} = ## returns true if the contents of the file `f` equal `r`. - var bufSize = 1024 # reasonable start value - var buf = alloc(bufSize) + var + buf: array[bufSize, char] + bpos = buf.len + blen = buf.len + for s in leaves(r): - if s.len > bufSize: - bufSize = max(bufSize * 2, s.len) - buf = realloc(buf, bufSize) - var readBytes = readBuffer(f, buf, s.len) - result = readBytes == s.len and equalMem(buf, cstring(s), s.len) - if not result: break - if result: - result = readBuffer(f, buf, 1) == 0 # really at the end of file? - dealloc(buf) + var spos = 0 + let slen = s.len + while spos < slen: + if bpos == blen: + # Read more data + bpos = 0 + blen = readBuffer(f, addr(buf[0]), buf.len) + if blen == 0: # no more data in file + result = false + return + let n = min(blen - bpos, slen - spos) + # TODO There's gotta be a better way of comparing here... + if not equalMem(addr(buf[bpos]), + cast[pointer](cast[int](cstring(s))+spos), n): + result = false + return + spos += n + bpos += n + + result = readBuffer(f, addr(buf[0]), 1) == 0 # check that we've read all -proc equalsFile*(r: Rope, f: string): bool {.rtl, extern: "nro$1Str".} = +proc equalsFile*(r: Rope, filename: string): bool {.rtl, extern: "nro$1Str".} = ## returns true if the contents of the file `f` equal `r`. If `f` does not ## exist, false is returned. - var bin: File - result = open(bin, f) + var f: File + result = open(f, filename) if result: - result = equalsFile(r, bin) - close(bin) + result = equalsFile(r, f) + close(f) new(N) # init dummy node for splay algorithm |