services/datamanager/summary/summary.go

   1 /* Computes Summary based on data read from API server. */
   2
   3 package summary
   4
   5 import (
   6         "encoding/gob"
   7         "flag"
   8         "fmt"
   9         "git.curoverse.com/arvados.git/sdk/go/logger"
  10         "git.curoverse.com/arvados.git/services/datamanager/collection"
  11         "git.curoverse.com/arvados.git/services/datamanager/keep"
  12         "git.curoverse.com/arvados.git/services/datamanager/loggerutil"
  13         "log"
  14         "os"
  15 )
  16
  17 var (
  18         // These are just used for development, to save network i/o
  19         writeDataTo  string
  20         readDataFrom string
  21 )
  22
  23 type serializedData struct {
  24         ReadCollections collection.ReadCollections
  25         KeepServerInfo  keep.ReadServers
  26 }
  27
  28 func init() {
  29         flag.StringVar(&writeDataTo,
  30                 "write-data-to",
  31                 "",
  32                 "Write summary of data received to this file. Used for development only.")
  33         flag.StringVar(&readDataFrom,
  34                 "read-data-from",
  35                 "",
  36                 "Avoid network i/o and read summary data from this file instead. Used for development only.")
  37 }
  38
  39 // Writes data we've read to a file.
  40 //
  41 // This is useful for development, so that we don't need to read all our data from the network every time we tweak something.
  42 //
  43 // This should not be used outside of development, since you'll be
  44 // working with stale data.
  45 func MaybeWriteData(arvLogger *logger.Logger,
  46         readCollections collection.ReadCollections,
  47         keepServerInfo keep.ReadServers) bool {
  48         if writeDataTo == "" {
  49                 return false
  50         } else {
  51                 summaryFile, err := os.Create(writeDataTo)
  52                 if err != nil {
  53                         loggerutil.FatalWithMessage(arvLogger,
  54                                 fmt.Sprintf("Failed to open %s: %v", writeDataTo, err))
  55                 }
  56                 defer summaryFile.Close()
  57
  58                 enc := gob.NewEncoder(summaryFile)
  59                 data := serializedData{
  60                         ReadCollections: readCollections,
  61                         KeepServerInfo:  keepServerInfo}
  62                 err = enc.Encode(data)
  63                 if err != nil {
  64                         loggerutil.FatalWithMessage(arvLogger,
  65                                 fmt.Sprintf("Failed to write summary data: %v", err))
  66                 }
  67                 log.Printf("Wrote summary data to: %s", writeDataTo)
  68                 return true
  69         }
  70 }
  71
  72 // Reads data that we've read to a file.
  73 //
  74 // This is useful for development, so that we don't need to read all our data from the network every time we tweak something.
  75 //
  76 // This should not be used outside of development, since you'll be
  77 // working with stale data.
  78 func MaybeReadData(arvLogger *logger.Logger,
  79         readCollections *collection.ReadCollections,
  80         keepServerInfo *keep.ReadServers) bool {
  81         if readDataFrom == "" {
  82                 return false
  83         } else {
  84                 summaryFile, err := os.Open(readDataFrom)
  85                 if err != nil {
  86                         loggerutil.FatalWithMessage(arvLogger,
  87                                 fmt.Sprintf("Failed to open %s: %v", readDataFrom, err))
  88                 }
  89                 defer summaryFile.Close()
  90
  91                 dec := gob.NewDecoder(summaryFile)
  92                 data := serializedData{}
  93                 err = dec.Decode(&data)
  94                 if err != nil {
  95                         loggerutil.FatalWithMessage(arvLogger,
  96                                 fmt.Sprintf("Failed to read summary data: %v", err))
  97                 }
  98                 log.Printf("Read summary data from: %s", readDataFrom)
  99                 return true
 100         }
 101 }