early work on scalding CDX backfill

1 files changed, 148 insertions, 0 deletions

diff --git a/scalding/src/main/scala/sandcrawler/CdxBackfillJob.scala b/scalding/src/main/scala/sandcrawler/CdxBackfillJob.scala
new file mode 100644
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+++ b/scalding/src/main/scala/sandcrawler/CdxBackfillJob.scala
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+package sandcrawler
+
+import cascading.property.AppProps
+import cascading.tuple.Fields
+import cascading.pipe.joiner._
+import com.twitter.scalding._
+import java.util.Properties
+import parallelai.spyglass.base.JobBase
+import parallelai.spyglass.hbase.{HBaseSource, HBasePipeConversions}
+import parallelai.spyglass.hbase.HBaseConstants.SourceMode
+
+// Type that represents a raw parsed CDX line
+case class CdxLine(surt: String, datetime: String, url: String, mime: String, http_status: String, sha1: String, c_size: String, offset: String, warc: String)
+
+/**
+ *  CDX backfill:
+ *  1. parse CDX (all columns)
+ *  2. filter CDX (pdf, HTTP 200, etc)
+ *  3. source HBase (key column only)
+ *  4. left join CDX to HBase
+ *  5. filter to only those with null HBase key column
+ *  6. convert CDX fields to HBase columns
+ *  7. sink results to HBase
+ *
+ * TODO: I really mixed the Scalding "field-base" and "type-based" APIs here.
+ * Should decide on a best practice.
+ */
+class CdxBackfillJob(args: Args) extends JobBase(args) with HBasePipeConversions {
+
+  //import CdxLine._
+  // XXX remove all other CdxBackfillJob.whatever
+  import CdxBackfillJob._
+
+  val cdxInputPath = args("cdx-input-path")
+  val hbaseTable = args("hbase-table")
+  val zookeeperHosts = args("zookeeper-hosts")
+
+  val hbaseSource = getHBaseSource(args("hbase-table"), args("zookeeper-hosts"))
+
+  val lines : TypedPipe[String] = TypedPipe.from(TextLine(cdxInputPath))
+
+  val cdxLines : TypedPipe[CdxLine] = lines
+    .filter { isCdxLine }
+    .map { lineToCdxLine }
+    .filter { CdxBackfillJob.keepCdx(_) }
+
+  val cdxRows = cdxLines
+    .map { CdxBackfillJob.cdxLineToRow(_) }
+    .toPipe(('key, 'f_c, 'file_cdx, 'file_mime))
+
+  val hbaseKeys = hbaseSource
+    .project('key)
+    .mapTo('key -> 'existingKey) { key : String => key }
+
+  // filters out all the lines that have an existing SHA1 key in HBase
+  val newRows = cdxRows
+    .joinWithLarger('key -> 'existingKey, hbaseKeys, joiner = new LeftJoin)
+    .filter('existingKey) { k : String => k == null } // is String the right type?
+
+  newRows
+    .write(hbaseSource)
+
+}
+
+object CdxBackfillJob {
+
+  def getHBaseSource(hbase_table: String, zookeeper_hosts: String) : HBaseSource = {
+    return HBaseBuilder.build(
+      hbase_table,
+      zookeeper_hosts,
+      List("file:size"), // not actually needed
+      SourceMode.SCAN_ALL)
+  }
+
+  def normalizeMime(raw: String) : String = {
+
+    val NORMAL_MIME = List("application/pdf",
+                           "application/postscript",
+                           "text/html",
+                           "text/xml")
+
+    val lower = raw.toLowerCase()
+    NORMAL_MIME.foreach(norm =>
+      if (lower.startsWith(norm)) {
+        return norm
+      }
+    )
+
+    // Common special cases
+    if (lower.startsWith("application/xml")) {
+      return "text/xml"
+    }
+    if (lower.startsWith("application/x-pdf")) {
+      return "application/pdf"
+    }
+    return lower
+
+  }
+
+  def isCdxLine(line: String) : Boolean = {
+    // malformated or non-CDX11 lines
+    !(line.startsWith("#") || line.startsWith(" ") || line.startsWith("filedesc") ||
+      line.split(" ").size != 11)
+  }
+
+  def keepCdx(line: CdxLine) : Boolean = {
+    // TODO: sha1.isalnum() and c_size.isdigit() and offset.isdigit() and dt.isdigit()
+    if (line.http_status != "200" || line.sha1.size != 32) {
+      return false
+    }
+    // TODO: '-' in (line.surt, line.datetime, line.url, line.mime, line.c_size, line.offset, line.warc)
+    return true
+  }
+
+  // Returns (key, f:c, file:cdx, file:mime), all as strings, which is close to
+  // how they will be inserted into HBase
+  def cdxLineToRow(line: CdxLine) : (String, String, String, String) = {
+
+    val key = "sha1:" + line.sha1
+
+    val warcFile = line.warc.split('/')(1)
+
+    // Read CDX-style datetime and conver to ISO 8601 with second resolution
+    val dtFormat = new java.text.SimpleDateFormat("yyyyMMddHHmmss")
+    val isoFormat = new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'")
+    // TODO: timezones? UTC to UTC, so I don't think so.
+    val dtIso = isoFormat.format(dtFormat.parse(line.datetime))
+
+    // warc_file = warc.split('/')[-1]
+    // dt_iso = datetime.strptime(dt, "%Y%m%d%H%M%S").isoformat()
+    // f:c = dict(u=url, d=dt_iso, f=warc_file, o=int(offset), c=1)
+
+    // This is the "f:c" field. 'i' intentionally not set
+    val heritrixInfo = ""
+
+    // file:cdx = dict(surt=surt, dt=dt, url=url, c_size=int(c_size),
+    //                 offset=int(offset), warc=warc)
+    val fileCdx = ""
+    (key, heritrixInfo, fileCdx, line.mime)
+  }
+
+  def lineToCdxLine(line: String) : CdxLine = {
+    val raw = line.split("\\s+")
+    // surt, datetime, url, mime, http_status, sha1, SKIP, SKIP, c_size, offset, warc
+    CdxLine(raw(0), raw(1), raw(2), raw(3), raw(4), raw(5), raw(8), raw(9), raw(10))
+  }
+
+}