From 2f410245517a62a37c3229174117ae319a042bff Mon Sep 17 00:00:00 2001
From: txh18 <cloudygooseg@gmail.com>
Date: Wed, 28 Oct 2015 17:53:46 +0800
Subject: TODO:implement lmseqreader

---
 nerv/examples/lmptb/lmptb/lmseqreader.lua        | 96 ++++++++++++++++++++++++
 nerv/examples/lmptb/m-tests/lmseqreader_test.lua | 19 +++++
 nerv/examples/lmptb/m-tests/some-text            | 10 +++
 3 files changed, 125 insertions(+)
 create mode 100644 nerv/examples/lmptb/lmptb/lmseqreader.lua
 create mode 100644 nerv/examples/lmptb/m-tests/lmseqreader_test.lua
 create mode 100644 nerv/examples/lmptb/m-tests/some-text

diff --git a/nerv/examples/lmptb/lmptb/lmseqreader.lua b/nerv/examples/lmptb/lmptb/lmseqreader.lua
new file mode 100644
index 0000000..0952842
--- /dev/null
+++ b/nerv/examples/lmptb/lmptb/lmseqreader.lua
@@ -0,0 +1,96 @@
+require 'lmptb.lmvocab'
+
+local LMReader = nerv.class("nerv.LMSeqReader")
+
+local printf = nerv.printf
+
+--global_conf: table
+--batch_size: int
+--vocab: nerv.LMVocab
+function LMReader:__init(global_conf, batch_size, vocab)
+    self.gconf = global_conf
+    self.fh = nil --file handle to read, nil means currently no file
+    self.batch_size = batch_size
+    self.log_pre = "[LOG]LMFeeder:"
+    self.vocab = vocab
+    self.streams = nil
+end
+
+--fn: string
+--Initialize all streams
+function LMReader:open_file(fn)
+    if (self.fh ~= nil) then
+        nerv.error("%s error: in open_file, file handle not nil.")
+    end
+    printf("%s opening file %s...\n", self.log_pre, fn)
+    self.fh = io.open(fn, "r")
+    self.streams = {}
+    for i = 1, self.batch_size, 1 do
+        self.streams[i] = {["store"] = {self.vocab.sen_end_token}, ["head"] = 1, ["tail"] = 1}
+    end
+end
+   
+--id: int
+--Refresh stream id,  read a line from file
+function LMReader:refresh_stream(id)
+    if (self.streams[id] == nil) then
+        nerv.error("stream %d does not exit.", id)
+    end
+    local st = self.streams[id]
+    if (st.store[st.head] ~= nil) then return end
+    if (self.fh == nil) then return end
+    local list = self.vocab:read_line(self.fh)
+    if (list == nil) then --file has end
+        printf("%s file expires, closing.\n", self.log_pre)
+        self.fh:close() 
+        self.fh = nil 
+        return 
+    end
+    for i = 1, #list, 1 do
+        st.tail = st.tail + 1
+        st.store[st.tail] = list[i]
+    end
+end
+
+--Returns: nil/table
+--If gets something, return a list of string, vocab.null_token indicates end of string
+function LMReader:get_batch()
+    local got_new = false
+    local list = {}
+    for i = 1, self.batch_size, 1 do
+        self:refresh_stream(i)
+        local st = self.streams[i]
+        list[i] = st.store[st.head]
+        if (list[i] == nil) then list[i] = self.vocab.null_token end
+        if (list[i] ~= nil and list[i] ~= self.vocab.null_token)then
+            got_new = true
+            st.store[st.head] = nil
+            st.head = st.head + 1
+        end 
+    end
+    if (got_new == false) then
+        return nil
+    else
+        return list
+    end
+end
+
+--[[
+do
+    local test_fn = "/home/slhome/txh18/workspace/nerv/nerv/some-text"
+    --local test_fn = "/home/slhome/txh18/workspace/nerv-project/nerv/examples/lmptb/PTBdata/ptb.train.txt"
+    local vocab = nerv.LMVocab()
+    vocab:build_file(test_fn)
+    local batch_size = 3
+    local feeder = nerv.LMFeeder({}, batch_size, vocab)
+    feeder:open_file(test_fn)
+    while (1) do
+        local list = feeder:get_batch()
+        if (list == nil) then break end
+        for i = 1, batch_size, 1 do
+            printf("%s(%d) ", list[i], vocab:get_word_str(list[i]).id) 
+        end
+        printf("\n")
+    end
+end
+]]--
diff --git a/nerv/examples/lmptb/m-tests/lmseqreader_test.lua b/nerv/examples/lmptb/m-tests/lmseqreader_test.lua
new file mode 100644
index 0000000..b90e651
--- /dev/null
+++ b/nerv/examples/lmptb/m-tests/lmseqreader_test.lua
@@ -0,0 +1,19 @@
+require 'lmptb.lmseqreader'
+
+local printf = nerv.printf
+
+local test_fn = "/home/slhome/txh18/workspace/nerv/nerv/nerv/examples/lmptb/m-tests/some-text"
+--local test_fn = "/home/slhome/txh18/workspace/nerv-project/nerv/examples/lmptb/PTBdata/ptb.train.txt"
+local vocab = nerv.LMVocab()
+vocab:build_file(test_fn)
+local batch_size = 3
+local reader = nerv.LMSeqReader({}, batch_size, vocab)
+reader:open_file(test_fn)
+while (1) do
+    local list = reader:get_batch()
+    if (list == nil) then break end
+    for i = 1, batch_size, 1 do
+        printf("%s(%d) ", list[i], vocab:get_word_str(list[i]).id) 
+    end
+    printf("\n")
+end
diff --git a/nerv/examples/lmptb/m-tests/some-text b/nerv/examples/lmptb/m-tests/some-text
new file mode 100644
index 0000000..e905b60
--- /dev/null
+++ b/nerv/examples/lmptb/m-tests/some-text
@@ -0,0 +1,10 @@
+aa bb cc aa bb cc aa bb cc aa bb cc aa bb cc aa
+aa bb cc aa bb cc aa bb cc aa
+aa bbcc aa bb cc aa bb cc aa
+aa bb cc aa
+aa bb cc aa
+aa bb cc aa
+aa
+aa bb cc aa
+aa bb cc aa
+aa bb cc aa bb cc aa
-- 
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