aboutsummaryrefslogtreecommitdiff
path: root/R/pkg/inst/worker/worker.R
blob: b6784dbae320346afb33f386929a104bef371506 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

# Worker class

# Get current system time
currentTimeSecs <- function() {
  as.numeric(Sys.time())
}

# Get elapsed time
elapsedSecs <- function() {
  proc.time()[3]
}

# Constants
specialLengths <- list(END_OF_STERAM = 0L, TIMING_DATA = -1L)

# Timing R process boot
bootTime <- currentTimeSecs()
bootElap <- elapsedSecs()

rLibDir <- Sys.getenv("SPARKR_RLIBDIR")
dirs <- strsplit(rLibDir, ",")[[1]]
# Set libPaths to include SparkR package as loadNamespace needs this
# TODO: Figure out if we can avoid this by not loading any objects that require
# SparkR namespace
.libPaths(c(dirs, .libPaths()))
suppressPackageStartupMessages(library(SparkR))

port <- as.integer(Sys.getenv("SPARKR_WORKER_PORT"))
inputCon <- socketConnection(port = port, blocking = TRUE, open = "rb")
outputCon <- socketConnection(port = port, blocking = TRUE, open = "wb")

# read the index of the current partition inside the RDD
partition <- SparkR:::readInt(inputCon)

deserializer <- SparkR:::readString(inputCon)
serializer <- SparkR:::readString(inputCon)

# Include packages as required
packageNames <- unserialize(SparkR:::readRaw(inputCon))
for (pkg in packageNames) {
  suppressPackageStartupMessages(library(as.character(pkg), character.only = TRUE))
}

# read function dependencies
funcLen <- SparkR:::readInt(inputCon)
computeFunc <- unserialize(SparkR:::readRawLen(inputCon, funcLen))
env <- environment(computeFunc)
parent.env(env) <- .GlobalEnv  # Attach under global environment.

# Timing init envs for computing
initElap <- elapsedSecs()

# Read and set broadcast variables
numBroadcastVars <- SparkR:::readInt(inputCon)
if (numBroadcastVars > 0) {
  for (bcast in seq(1:numBroadcastVars)) {
    bcastId <- SparkR:::readInt(inputCon)
    value <- unserialize(SparkR:::readRaw(inputCon))
    SparkR:::setBroadcastValue(bcastId, value)
  }
}

# Timing broadcast
broadcastElap <- elapsedSecs()

# If -1: read as normal RDD; if >= 0, treat as pairwise RDD and treat the int
# as number of partitions to create.
numPartitions <- SparkR:::readInt(inputCon)

isEmpty <- SparkR:::readInt(inputCon)

if (isEmpty != 0) {

  if (numPartitions == -1) {
    if (deserializer == "byte") {
      # Now read as many characters as described in funcLen
      data <- SparkR:::readDeserialize(inputCon)
    } else if (deserializer == "string") {
      data <- as.list(readLines(inputCon))
    } else if (deserializer == "row") {
      data <- SparkR:::readMultipleObjects(inputCon)
    }
    # Timing reading input data for execution
    inputElap <- elapsedSecs()

    output <- computeFunc(partition, data)
    # Timing computing
    computeElap <- elapsedSecs()

    if (serializer == "byte") {
      SparkR:::writeRawSerialize(outputCon, output)
    } else if (serializer == "row") {
      SparkR:::writeRowSerialize(outputCon, output)
    } else {
      # write lines one-by-one with flag
      lapply(output, function(line) SparkR:::writeString(outputCon, line))
    }
    # Timing output
    outputElap <- elapsedSecs()
  } else {
    if (deserializer == "byte") {
      # Now read as many characters as described in funcLen
      data <- SparkR:::readDeserialize(inputCon)
    } else if (deserializer == "string") {
      data <- readLines(inputCon)
    } else if (deserializer == "row") {
      data <- SparkR:::readMultipleObjects(inputCon)
    }
    # Timing reading input data for execution
    inputElap <- elapsedSecs()

    res <- new.env()

    # Step 1: hash the data to an environment
    hashTupleToEnvir <- function(tuple) {
      # NOTE: execFunction is the hash function here
      hashVal <- computeFunc(tuple[[1]])
      bucket <- as.character(hashVal %% numPartitions)
      acc <- res[[bucket]]
      # Create a new accumulator
      if (is.null(acc)) {
        acc <- SparkR:::initAccumulator()
      }
      SparkR:::addItemToAccumulator(acc, tuple)
      res[[bucket]] <- acc
    }
    invisible(lapply(data, hashTupleToEnvir))
    # Timing computing
    computeElap <- elapsedSecs()

    # Step 2: write out all of the environment as key-value pairs.
    for (name in ls(res)) {
      SparkR:::writeInt(outputCon, 2L)
      SparkR:::writeInt(outputCon, as.integer(name))
      # Truncate the accumulator list to the number of elements we have
      length(res[[name]]$data) <- res[[name]]$counter
      SparkR:::writeRawSerialize(outputCon, res[[name]]$data)
    }
    # Timing output
    outputElap <- elapsedSecs()
  }
} else {
  inputElap <- broadcastElap
  computeElap <- broadcastElap
  outputElap <- broadcastElap
}

# Report timing
SparkR:::writeInt(outputCon, specialLengths$TIMING_DATA)
SparkR:::writeDouble(outputCon, bootTime)
SparkR:::writeDouble(outputCon, initElap - bootElap)        # init
SparkR:::writeDouble(outputCon, broadcastElap - initElap)   # broadcast
SparkR:::writeDouble(outputCon, inputElap - broadcastElap)  # input
SparkR:::writeDouble(outputCon, computeElap - inputElap)    # compute
SparkR:::writeDouble(outputCon, outputElap - computeElap)   # output

# End of output
SparkR:::writeInt(outputCon, specialLengths$END_OF_STERAM)

close(outputCon)
close(inputCon)