Change the timeout handling

it is better to set the timeout setting only at instantiation.

.github/workflows/test.yml

@@ -54,6 +54,8 @@ jobs:
         luarocks install luacov
         luarocks install testcase
         luarocks install assert
+        luarocks install os-pipe
+        luarocks install time-clock
     -
       name: Install
       run: |

README.md

@@ -18,13 +18,14 @@ luarocks install io-reader
 the following functions return the `error` object created by https://github.com/mah0x211/lua-errno module.
 
 
-## r, err = io.reader.new(f)
+## r, err = io.reader.new( f [, sec] )
 
 create a new reader instance that reads data from a file or file descriptor.
 
 **Parameters**
 
 - `f:file*|string|integer`: file, filename or file descriptor.
+- `sec:number`: timeout seconds. (default `nil` means no timeout)
 
 **Returns**
 
@@ -63,17 +64,16 @@ print(dump({
 ```
 
 
-## s, err, timeout = reader:read(fmt, sec)
+## s, err, timeout = reader:read( [fmt] )
 
 read data from the file or file descriptor.
 
 **Parameters**
 
 - `fmt:integer|string`: size of data to read, or format string as follows: (`*` prefix can be omitted)
-  - `*a`: reads all data.
   - `*l`: reads a line. (default)
   - `*L`: reads a line with the newline character.
-- `sec:number`: timeout seconds.
+  - `*a`: reads all data.
 
 **Returns**
 

reader.lua

@@ -32,17 +32,20 @@ local wait_readable = require('gpoll').wait_readable
 --- @class io.reader
 --- @field private fd integer
 --- @field private file? file*
+--- @field private waitsec? number
 --- @field private buf string
 local Reader = {}
 
 --- init
 --- @param fd integer
 --- @param f file*
+--- @param sec number?
 --- @return io.reader
-function Reader:init(fd, f)
+function Reader:init(fd, f, sec)
     self.fd = fd
     self.file = f
     self.buf = ''
+    self.waitsec = sec
     return self
 end
 
@@ -68,14 +71,12 @@ end
 --- read
 --- wait_readable
 --- @param fmt string|integer?
---- @param sec number?
 --- @return string? data
 --- @return any err
 --- @return boolean? timeout
-function Reader:read(fmt, sec)
+function Reader:read(fmt)
     assert(fmt == nil or type(fmt) == 'number' or type(fmt) == 'string',
            'fmt must be integer, string or nil')
-    assert(sec == nil or type(sec) == 'number', 'sec must be number or nil')
 
     local t = type(fmt)
     if t == 'number' then
@@ -90,7 +91,7 @@ function Reader:read(fmt, sec)
         local buf = self.buf
         local len = #buf
         if len < n then
-            local data, err, timeout = read(self.fd, n - len, sec)
+            local data, err, timeout = read(self.fd, n - len, self.waitsec)
             if not data then
                 return nil, err, timeout
             end
@@ -120,14 +121,14 @@ function Reader:read(fmt, sec)
             return buf
         end
         -- read all data from the file
-        return read(self.fd, nil, sec)
+        return read(self.fd, nil, self.waitsec)
     end
 
     local buf = self.buf
     local head, tail = find(buf, '\r?\n', 1)
     while not head do
         -- need to read more data
-        local data, err, timeout = read(self.fd, nil, sec)
+        local data, err, timeout = read(self.fd, nil, self.waitsec)
         if not data then
             return nil, err, timeout
         end
@@ -155,9 +156,12 @@ Reader = require('metamodule').new(Reader)
 
 --- new
 --- @param file string|integer|file*
+--- @param sec number?
 --- @return io.reader? rdr
 --- @return any err
-local function new(file)
+local function new(file, sec)
+    assert(sec == nil or type(sec) == 'number', 'sec must be number or nil')
+
     local t = type(file)
     local f, err
     if isfile(file) then
@@ -174,7 +178,7 @@ local function new(file)
     if not f then
         return nil, err
     end
-    return Reader(fileno(f), f)
+    return Reader(fileno(f), f, sec)
 end
 
 return {

test/reader_test.lua

@@ -3,6 +3,8 @@ local testcase = require('testcase')
 local assert = require('assert')
 local fileno = require('io.fileno')
 local reader = require('io.reader')
+local pipe = require('os.pipe')
+local gettime = require('time.clock').gettime
 
 local TEST_TXT = 'test.txt'
 
@@ -25,6 +27,11 @@ function testcase.new()
     assert.is_nil(err)
     assert.match(r, '^io.reader: ', false)
 
+    -- test that create a new reader from file with timeout seconds
+    r, err = reader.new(f, 1)
+    assert.is_nil(err)
+    assert.match(r, '^io.reader: ', false)
+
     -- test that create a new reader from filename
     r, err = reader.new(TEST_TXT)
     assert.is_nil(err)
@@ -40,6 +47,13 @@ function testcase.new()
     assert.is_nil(err)
     assert.match(r, '^io.reader: ', false)
 
+    -- test that create a new reader from pipe file descriptor
+    local pr, _, perr = pipe(true)
+    assert(perr == nil, perr)
+    r, err = reader.new(pr:fd())
+    assert.is_nil(err)
+    assert.match(r, '^io.reader: ', false)
+
     -- test that return err if file descriptor is invalid
     r, err = reader.new(-1)
     assert.is_nil(r)
@@ -49,6 +63,10 @@ function testcase.new()
     r, err = reader.new(true)
     assert.is_nil(r)
     assert.match(err, 'FILE*, pathname or file descriptor expected, got boolean')
+
+    -- test that throws an error if invalid sec argument
+    err = assert.throws(reader.new, f, true)
+    assert.match(err, 'sec must be number or nil')
 end
 
 function testcase.read_with_format_string()
@@ -112,3 +130,38 @@ function testcase.read_nbyte()
     err = assert.throws(r.read, r, -1)
     assert.match(err, 'negative number')
 end
+
+function testcase.read_with_timeout()
+    local pr, pw, perr = pipe(true)
+    assert(perr == nil, perr)
+
+    -- test that read timeout after 0.5 second
+    local r = assert(reader.new(pr:fd(), .5))
+    local t = gettime()
+    local s, err, again = r:read()
+    t = gettime() - t
+    assert.is_nil(err)
+    assert.is_nil(s)
+    assert.is_true(again)
+    assert.is_true(t >= .5 and t < .6)
+
+    -- test that read line from pipe
+    pw:write('hello\nworld!\n')
+    s, err, again = r:read()
+    assert.is_nil(err)
+    assert.is_nil(again)
+    assert.equal(s, 'hello')
+
+    -- test that read line from pipe even if peer of pipe is closed
+    pw:close()
+    s, err, again = r:read()
+    assert.is_nil(err)
+    assert.is_nil(again)
+    assert.equal(s, 'world!')
+
+    -- test that return nil if eof
+    s, err, again = r:read()
+    assert.is_nil(s)
+    assert.is_nil(err)
+    assert.is_nil(again)
+end