package sbt
import java.io.File
import CacheIO.{fromFile, toFile}
import sbinary.Format
import scala.reflect.Manifest
import scala.collection.mutable
import IO.{delete, read, write}
object Tracked
{
def tstamp(cacheFile: File, useStartTime: Boolean = true): Timestamp = new Timestamp(cacheFile, useStartTime)
def diffInputs(cache: File, style: FilesInfo.Style): Difference =
Difference.inputs(cache, style)
def diffOutputs(cache: File, style: FilesInfo.Style): Difference =
Difference.outputs(cache, style)
def lastOutput[I,O](cacheFile: File)(f: (I,Option[O]) => O)(implicit o: Format[O], mf: Manifest[Format[O]]): I => O = in =>
{
val previous: Option[O] = fromFile[O](cacheFile)
val next = f(in, previous)
toFile(next)(cacheFile)
next
}
def inputChanged[I,O](cacheFile: File)(f: (Boolean, I) => O)(implicit ic: InputCache[I]): I => O = in =>
{
val help = new CacheHelp(ic)
val conv = help.convert(in)
val changed = help.changed(cacheFile, conv)
val result = f(changed, in)
if(changed)
help.save(cacheFile, conv)
result
}
def outputChanged[I,O](cacheFile: File)(f: (Boolean, I) => O)(implicit ic: InputCache[I]): (() => I) => O = in =>
{
val initial = in()
val help = new CacheHelp(ic)
val changed = help.changed(cacheFile, help.convert(initial))
val result = f(changed, initial)
if(changed)
help.save(cacheFile, help.convert(in()))
result
}
final class CacheHelp[I](val ic: InputCache[I])
{
def convert(i: I): ic.Internal = ic.convert(i)
def save(cacheFile: File, value: ic.Internal): Unit =
Using.fileOutputStream()(cacheFile)(out => ic.write(out, value) )
def changed(cacheFile: File, converted: ic.Internal): Boolean =
try {
val prev = Using.fileInputStream(cacheFile)(x => ic.read(x))
!ic.equiv.equiv(converted, prev)
} catch { case e: Exception => true }
}
}
trait Tracked
{
def clean: Unit
}
class Timestamp(val cacheFile: File, useStartTime: Boolean) extends Tracked
{
def clean = delete(cacheFile)
def apply[T](f: Long => T): T =
{
val start = now()
val result = f(readTimestamp)
write(cacheFile, (if(useStartTime) start else now()).toString)
result
}
private def now() = System.currentTimeMillis
def readTimestamp: Long =
try { read(cacheFile).toLong }
catch { case _: NumberFormatException | _: java.io.FileNotFoundException => 0 }
}
class Changed[O](val cacheFile: File)(implicit equiv: Equiv[O], format: Format[O]) extends Tracked
{
def clean = delete(cacheFile)
def apply[O2](ifChanged: O => O2, ifUnchanged: O => O2): O => O2 = value =>
{
if(uptodate(value))
ifUnchanged(value)
else
{
update(value)
ifChanged(value)
}
}
def update(value: O): Unit = Using.fileOutputStream(false)(cacheFile)(stream => format.writes(stream, value))
def uptodate(value: O): Boolean =
try {
Using.fileInputStream(cacheFile) {
stream => equiv.equiv(value, format.reads(stream))
}
} catch {
case _: Exception => false
}
}
object Difference
{
def constructor(defineClean: Boolean, filesAreOutputs: Boolean): (File, FilesInfo.Style) => Difference =
(cache, style) => new Difference(cache, style, defineClean, filesAreOutputs)
val outputs = constructor(true, true)
val inputs = constructor(false, false)
}
class Difference(val cache: File, val style: FilesInfo.Style, val defineClean: Boolean, val filesAreOutputs: Boolean) extends Tracked
{
def clean =
{
if(defineClean) delete(raw(cachedFilesInfo)) else ()
clearCache()
}
private def clearCache() = delete(cache)
private def cachedFilesInfo = fromFile(style.formats, style.empty)(cache)(style.manifest).files
private def raw(fs: Set[style.F]): Set[File] = fs.map(_.file)
def apply[T](files: Set[File])(f: ChangeReport[File] => T): T =
{
val lastFilesInfo = cachedFilesInfo
apply(files, lastFilesInfo)(f)(_ => files)
}
def apply[T](f: ChangeReport[File] => T)(implicit toFiles: T => Set[File]): T =
{
val lastFilesInfo = cachedFilesInfo
apply(raw(lastFilesInfo), lastFilesInfo)(f)(toFiles)
}
private def abs(files: Set[File]) = files.map(_.getAbsoluteFile)
private[this] def apply[T](files: Set[File], lastFilesInfo: Set[style.F])(f: ChangeReport[File] => T)(extractFiles: T => Set[File]): T =
{
val lastFiles = raw(lastFilesInfo)
val currentFiles = abs(files)
val currentFilesInfo = style(currentFiles)
val report = new ChangeReport[File]
{
lazy val checked = currentFiles
lazy val removed = lastFiles -- checked
lazy val added = checked -- lastFiles
lazy val modified = raw(lastFilesInfo -- currentFilesInfo.files) ++ added
lazy val unmodified = checked -- modified
}
val result = f(report)
val info = if(filesAreOutputs) style(abs(extractFiles(result))) else currentFilesInfo
toFile(style.formats)(info)(cache)(style.manifest)
result
}
}
object FileFunction {
type UpdateFunction = (ChangeReport[File], ChangeReport[File]) => Set[File]
def cached(cacheBaseDirectory: File, inStyle: FilesInfo.Style = FilesInfo.lastModified, outStyle: FilesInfo.Style = FilesInfo.exists)(action: Set[File] => Set[File]): Set[File] => Set[File] =
cached(cacheBaseDirectory)(inStyle, outStyle)( (in, out) => action(in.checked) )
def cached(cacheBaseDirectory: File)(inStyle: FilesInfo.Style, outStyle: FilesInfo.Style)(action: UpdateFunction): Set[File] => Set[File] =
{
import Path._
lazy val inCache = Difference.inputs(cacheBaseDirectory / "in-cache", inStyle)
lazy val outCache = Difference.outputs(cacheBaseDirectory / "out-cache", outStyle)
inputs =>
{
inCache(inputs) { inReport =>
outCache { outReport =>
if(inReport.modified.isEmpty && outReport.modified.isEmpty)
outReport.checked
else
action(inReport, outReport)
}
}
}
}
}