main.swift

import Glibc
import Sua
import CSua


var count = 0

func trackDir(pathBytes: [UInt8]) {
  let cap = UnsafePointer<CChar>(pathBytes)
  guard let dp = opendir(cap) else {
    // Ignore in case permission denies access to the directory.
    return
  }
  defer {
    closedir(dp)
  }
  var entry = readdir(dp)
  while entry != nil {
    count += 1
    if entry!.pointee.d_type == 4 {
      var dirName = entry!.pointee.d_name
      withUnsafePointer(&dirName) { ptr in
        let len = Int(Sys.strlen(sp: UnsafePointer<CChar>(ptr)))
        let b = UnsafeBufferPointer<UInt8>(start: UnsafePointer<UInt8>(ptr),
            count: len)
        if len <= 2 && b[0] == 46 && (len == 1 || b[1] == 46) {
          // Ignore Dot file: . ..
        } else {
          var cp = [UInt8]()
          cp.reserveCapacity(pathBytes.count + len + 1)
          cp += pathBytes
          cp.removeLast() // Remove null-byte 0
          cp += b
          cp.append(47)
          cp.append(0) // Now append the trailing null-byte 0
          trackDir(pathBytes: cp)
        }
      }
    }
    entry = readdir(dp)
  }
}

func spelunkDir(path: String) {
  guard let dp = opendir(path) else {
    // Ignore in case permission denies access to the directory.
    return
  }
  defer {
    closedir(dp)
  }
  var entry = readdir(dp)
  while entry != nil {
    count += 1
    if entry!.pointee.d_type == 4 {
      var dirName = entry!.pointee.d_name
      withUnsafePointer(&dirName) { ptr in
        let name = String(cString: UnsafePointer<CChar>(ptr))
        if name != "." && name != ".." {
          spelunkDir(path: "\(path)\(name)/")
        }
      }
    }
    entry = readdir(dp)
  }
}

func browseDir(pathBytes: [UInt8]) throws {
  do {
    let fb = try FileBrowser(pathBytes: pathBytes)
    while fb.next() {
      count += 1
      if fb.type == .D {
        let nameBytes = fb.nameBytes
        let len = nameBytes.count
        if len <= 2 && nameBytes[0] == 46 && (len == 1 || nameBytes[1] == 46) {
          // Ignore Dot file: . ..
        } else {
          var cp = [UInt8]()
          cp.reserveCapacity(pathBytes.count + nameBytes.count + 1)
          cp += pathBytes
          cp.removeLast() // Remove null-byte 0
          cp += nameBytes
          cp.append(47)
          cp.append(0) // Now append the trailing null-byte 0
          try browseDir(pathBytes: cp)
        }
      }
    }
  } catch {
    // Ignore in case of errors or denied permission.
  }
}

func browseDir2(pathBytes: [UInt8]) throws {
  do {
    let fb = try FileBrowser(pathBytes: pathBytes)
    while fb.next() {
      count += 1
      if fb.type == .D {
        var rn = fb.rawEntry.pointee.d_name
        try withUnsafePointer(&rn) { ptr in
          let len = Int(Sys.strlen(sp: UnsafePointer<CChar>(ptr)))
          let b = UnsafeBufferPointer<UInt8>(start: UnsafePointer<UInt8>(ptr),
              count: len)
          if len <= 2 && b[0] == 46 && (len == 1 || b[1] == 46) {
            // Ignore Dot file: . ..
          } else {
            var cp = [UInt8]()
            cp.reserveCapacity(pathBytes.count + len + 1)
            cp += pathBytes
            cp.removeLast() // Remove null-byte 0
            cp += b
            cp.append(47)
            cp.append(0) // Now append the trailing null-byte 0
            try browseDir2(pathBytes: cp)
          }
        }
      }
    }
  } catch {
    // Ignore in case of errors or denied permission.
  }
}

func peekDir(pathBytes: [UInt8]) {
  var pb = pathBytes
  var store = [([UInt8], OpaquePointer?)]()
  store.reserveCapacity(128)
  PATH: while store.count >= 0 { // Trick the compiler.
    let cap = UnsafePointer<CChar>(pb)
    var dp = opendir(cap)
    if dp == nil {
      // Ignore in case permission denies access to the directory.
      if store.count > 0 {
        (pb, dp) = store.removeLast()
      } else {
        break PATH
      }
    }
    DIRP: while store.count >= 0 { // Trick the compiler.
      var entry = readdir(dp!)
      while entry != nil {
        count += 1
        if entry!.pointee.d_type == 4 {
          var dirName = entry!.pointee.d_name
          var ignore = true
          withUnsafePointer(&dirName) { ptr in
            let len = Int(Sys.strlen(sp: UnsafePointer<CChar>(ptr)))
            let b = UnsafeBufferPointer<UInt8>(start: UnsafePointer<UInt8>(ptr),
                count: len)
            if len <= 2 && b[0] == 46 && (len == 1 || b[1] == 46) {
              // Ignore Dot file: . ..
            } else {
              var cp = [UInt8]()
              cp.reserveCapacity(pb.count + len + 1)
              cp += pb
              cp.removeLast() // Remove null-byte 0
              cp += b
              cp.append(47)
              cp.append(0) // Now append the trailing null-byte 0
              store.append((pb, dp!))
              pb = cp
              ignore = false
            }
          }
          if !ignore {
            continue PATH
          }
        }
        entry = readdir(dp!)
      }
      closedir(dp!)
      if store.count > 0 {
        (pb, dp) = store.removeLast()
        continue DIRP
      } else {
        break PATH
      }
    }
  }
}



var sw = Stopwatch()
var samplePath = "/"
var a = [UInt8](samplePath.utf8)
a.append(0)
sw.start()
trackDir(pathBytes: a)
p("trackDir   count: \(count) Elapsed: \(sw.millis)")

count = 0
sw.start()
spelunkDir(path: samplePath)
p("spelunkDir count: \(count) Elapsed: \(sw.millis)")

count = 0
sw.start()
try browseDir(pathBytes: a)
p("browseDir  count: \(count) Elapsed: \(sw.millis)")

count = 0
sw.start()
try browseDir2(pathBytes: a)
p("browseDir2 count: \(count) Elapsed: \(sw.millis)")

count = 0
sw.start()
peekDir(pathBytes: a)
p("peekDir    count: \(count) Elapsed: \(sw.millis)")

count = 0
sw.start()
trackDir(pathBytes: a)
p("**trackDir count: \(count) Elapsed: \(sw.millis)")