/* Title: Pure/ML/ml_heap.scala
Author: Makarius
ML heap operations.
*/
package isabelle
import java.nio.ByteBuffer
import java.nio.channels.FileChannel
import java.nio.file.StandardOpenOption
object ML_Heap {
/** heap file with SHA1 digest **/
private val sha1_prefix = "SHA1:"
def read_file_digest(heap: Path): Option[SHA1.Digest] = {
if (heap.is_file) {
val l = sha1_prefix.length
val m = l + SHA1.digest_length
val n = File.size(heap)
val bs = Bytes.read_file(heap, offset = n - m)
if (bs.length == m) {
val s = bs.text
if (s.startsWith(sha1_prefix)) Some(SHA1.fake_digest(s.substring(l)))
else None
}
else None
}
else None
}
def write_file_digest(heap: Path): SHA1.Digest =
read_file_digest(heap) getOrElse {
val digest = SHA1.digest(heap)
File.append(heap, sha1_prefix + digest.toString)
digest
}
/* SQL data model */
object private_data extends SQL.Data("isabelle_heaps") {
override lazy val tables = SQL.Tables(Base.table, Slices.table)
object Generic {
val name = SQL.Column.string("name").make_primary_key
}
object Base {
val name = Generic.name
val size = SQL.Column.long("size")
val digest = SQL.Column.string("digest")
val table = make_table(List(name, size, digest))
}
object Slices {
val name = Generic.name
val slice = SQL.Column.int("slice").make_primary_key
val content = SQL.Column.bytes("content")
val table = make_table(List(name, slice, content), name = "slices")
}
object Slices_Size {
val name = Generic.name
val slice = SQL.Column.int("slice").make_primary_key
val size = SQL.Column.long("size")
val table = make_table(List(name, slice, size),
body = "SELECT name, slice, pg_size_pretty(length(content)::bigint) as size FROM " +
Slices.table.ident,
name = "slices_size")
}
def get_entries(db: SQL.Database, names: Iterable[String]): Map[String, SHA1.Digest] = {
require(names.nonEmpty)
db.execute_query_statement(
Base.table.select(List(Base.name, Base.digest),
sql = Generic.name.where_member(names)),
List.from[(String, String)],
res => res.string(Base.name) -> res.string(Base.digest)
).flatMap({
case (_, "") => None
case (name, digest) => Some(name -> SHA1.fake_digest(digest))
}).toMap
}
def read_entry(db: SQL.Database, name: String): List[Bytes] =
db.execute_query_statement(
Slices.table.select(List(Slices.content),
sql = Generic.name.where_equal(name) + SQL.order_by(List(Slices.slice))),
List.from[Bytes], _.bytes(Slices.content))
def clean_entry(db: SQL.Database, name: String): Unit = {
for (table <- List(Base.table, Slices.table)) {
db.execute_statement(table.delete(sql = Base.name.where_equal(name)))
}
db.create_view(Slices_Size.table)
}
def prepare_entry(db: SQL.Database, name: String): Unit =
db.execute_statement(Base.table.insert(), body =
{ stmt =>
stmt.string(1) = name
stmt.long(2) = None
stmt.string(3) = None
})
def write_entry(db: SQL.Database, name: String, slice: Int, content: Bytes): Unit =
db.execute_statement(Slices.table.insert(), body =
{ stmt =>
stmt.string(1) = name
stmt.int(2) = slice
stmt.bytes(3) = content
})
def finish_entry(db: SQL.Database, name: String, size: Long, digest: SHA1.Digest): Unit =
db.execute_statement(
Base.table.update(List(Base.size, Base.digest), sql = Base.name.where_equal(name)),
body =
{ stmt =>
stmt.long(1) = size
stmt.string(2) = digest.toString
})
}
def clean_entry(db: SQL.Database, session_name: String): Unit =
private_data.transaction_lock(db, create = true, label = "ML_Heap.clean_entry") {
private_data.clean_entry(db, session_name)
}
def get_entries(db: SQL.Database, names: Iterable[String]): Map[String, SHA1.Digest] =
private_data.transaction_lock(db, create = true, label = "ML_Heap.get_entries") {
private_data.get_entries(db, names)
}
def store(
database: Option[SQL.Database],
session_name: String,
heap: Path,
slice: Long,
cache: Compress.Cache = Compress.Cache.none
): SHA1.Digest = {
val digest = write_file_digest(heap)
database match {
case None =>
case Some(db) =>
val size = File.size(heap) - sha1_prefix.length - SHA1.digest_length
val slices = (size.toDouble / slice.toDouble).ceil.toInt
val step = (size.toDouble / slices.toDouble).ceil.toLong
try {
private_data.transaction_lock(db, create = true, label = "ML_Heap.store1") {
private_data.prepare_entry(db, session_name)
}
for (i <- 0 until slices) {
val j = i + 1
val offset = step * i
val limit = if (j < slices) step * j else size
val content =
Bytes.read_file(heap, offset = offset, limit = limit)
.compress(cache = cache)
private_data.transaction_lock(db, label = "ML_Heap.store2") {
private_data.write_entry(db, session_name, i, content)
}
}
private_data.transaction_lock(db, label = "ML_Heap.store3") {
private_data.finish_entry(db, session_name, size, digest)
}
}
catch { case exn: Throwable =>
private_data.transaction_lock(db, create = true, label = "ML_Heap.store4") {
private_data.clean_entry(db, session_name)
}
throw exn
}
}
digest
}
def restore(
database: Option[SQL.Database],
heaps: List[Path],
cache: Compress.Cache = Compress.Cache.none
): Unit = {
database match {
case Some(db) if heaps.nonEmpty =>
private_data.transaction_lock(db, create = true, label = "ML_Heap.restore") {
val db_digests = private_data.get_entries(db, heaps.map(_.file_name))
for (heap <- heaps) {
val session_name = heap.file_name
val file_digest = read_file_digest(heap)
val db_digest = db_digests.get(session_name)
if (db_digest.isDefined && db_digest != file_digest) {
val base_dir = Isabelle_System.make_directory(heap.expand.dir)
Isabelle_System.with_tmp_file(session_name + "_", base_dir = base_dir.file) { tmp =>
Bytes.write(tmp, Bytes.empty)
for (slice <- private_data.read_entry(db, session_name)) {
Bytes.append(tmp, slice.uncompress(cache = cache))
}
val digest = write_file_digest(tmp)
if (db_digest.get == digest) {
Isabelle_System.chmod("a+r", tmp)
Isabelle_System.move_file(tmp, heap)
}
else error("Incoherent content for session heap " + quote(session_name))
}
}
}
}
case _ =>
}
}
}