Implement timeout feature (#45)

* Implement timeout feature

* Add test for timeout, and doc string for set_timeout

* reduce timeout time in timeout_test

* Added CURLOPT_CONNECTTIMEOUT option along with CURLOPT_TIMEOUT

* change test url for auth

* update postman-echo/basic-auth url

Author: rajkumardongre

example/timeout.f90

@@ -0,0 +1,18 @@
+program timeout
+    ! This program demonstrates the use of the timeout option. The request below is designed
+    ! to take more than 10 seconds to complete, but we set the timeout value to 5 seconds.
+    ! As a result, the request will fail with an error message that says "Timeout was reached".
+    use http, only: response_type, request
+    implicit none
+    type(response_type) :: response
+
+    ! Delay in response for 10 seconds
+    response = request(url='https://httpbin.org/delay/10', timeout=5)
+    if(.not. response%ok) then
+        print *,'Error message : ', response%err_msg
+    else
+        print *, 'Response Code    : ', response%status_code
+        print *, 'Response Content : ', response%content
+    end if
+
+end program timeout

src/http/http_client.f90

@@ -20,6 +20,7 @@ module http_client
         CURLOPT_POSTFIELDS, CURLOPT_POSTFIELDSIZE_LARGE, curl_easy_escape, &
         curl_mime_init, curl_mime_addpart, curl_mime_filedata,curl_mime_name, &
         CURLOPT_MIMEPOST,curl_mime_data, CURL_ZERO_TERMINATED, &
+        CURLOPT_TIMEOUT, CURLOPT_CONNECTTIMEOUT, &
         CURLOPT_HTTPAUTH, CURLAUTH_BASIC, CURLOPT_USERNAME, CURLOPT_PASSWORD
     use stdlib_optval, only: optval
     use http_request, only: request_type
@@ -54,7 +55,7 @@ module http_client
     ! new client_type object using the request object as a parameter and sends the request to the server
     ! using the client_get_response method. The function returns the response_type object containing the
     ! server's response.
-    function new_request(url, method, header, data, form, file, auth) result(response)
+    function new_request(url, method, header, data, form, file, timeout, auth) result(response)
         !! This function creates a new HTTP request object of the request_type type and sends 
         !! the request to the server using the client_type object. The function takes the URL, 
         !! HTTP method, request headers, request data, and form data as input arguments and returns 
@@ -72,6 +73,8 @@ function new_request(url, method, header, data, form, file, auth) result(respons
             !! An optional array of pair_type objects that specifies the form data to send in the request body.
         type(pair_type), intent(in), optional :: file
             !! An optional pair_type object that specifies the file data to send in the request body.
+        integer, intent(in), optional :: timeout
+            !! Timeout value for the request in seconds
         type(pair_type), intent(in), optional :: auth
             !! An optional pair_type object that stores the username and password for Authentication
         type(response_type) :: response
@@ -112,6 +115,9 @@ function new_request(url, method, header, data, form, file, auth) result(respons
             request%file = file
         end if
 
+        ! Set request timeout.
+        request%timeout = optval(timeout, -1)
+                
         ! setting username and password for Authentication
         if(present(auth)) then
             request%auth = auth
@@ -168,6 +174,9 @@ & function failed. This can occur due to insufficient memory available in the sy
         ! setting request method
         rc = set_method(curl_ptr, this%request%method, response)
 
+        ! setting request timeout
+        rc = set_timeout(curl_ptr, this%request%timeout)
+
         ! setting request body
         rc = set_body(curl_ptr, this%request)
 
@@ -300,6 +309,25 @@ function set_method(curl_ptr, method, response) result(status)
         end select
     end function set_method
 
+    function set_timeout(curl_ptr, timeout) result(status)
+        !! This function sets the timeout value (in seconds). If the timeout value 
+        !! is less than zero, it is ignored and a success status is returned. 
+        type(c_ptr), intent(out) :: curl_ptr
+            !! Pointer to the curl handle.
+        integer(kind=int64), intent(in) :: timeout
+            !! Timeout seconds for request.
+        integer :: status
+            !! Status code indicating whether the operation was successful.
+        if(timeout < 0) then
+            status = 0
+        else
+            ! setting the maximum time allowed for the connection to established.(in seconds)
+            status = curl_easy_setopt(curl_ptr, CURLOPT_CONNECTTIMEOUT, timeout)
+            ! setting maximum time allowed for transfer operation.(in seconds)
+            status = curl_easy_setopt(curl_ptr, CURLOPT_TIMEOUT, timeout)
+        end if
+    end function set_timeout
+
     ! The set_body function determines the type of data to include in the request body 
     ! based on the inputs provided. If data is provided, it is sent as the body of the 
     ! request. If form is provided without a file, the form data is URL encoded and sent 

src/http/http_request.f90

@@ -3,7 +3,7 @@ module http_request
     !! This module contains the definition of a request_type derived type, which 
     !! represents an HTTP request.
 
-    ! use http_form , only: pair_type
+    use iso_fortran_env, only: int64
     use http_pair, only: pair_type
     use stdlib_string_type, only: string_type, to_lower, operator(==), char
 
@@ -38,6 +38,7 @@ module http_request
             !! An array of fields in an HTTP form.
         type(pair_type), allocatable :: file
             !! Used to store information about files to be sent in HTTP requests.
+        integer(kind=int64) :: timeout
         type(pair_type), allocatable :: auth
             !! Stores the username and password for Authentication
     end type request_type

test/test_auth.f90

@@ -9,8 +9,8 @@ program test_auth
     type(pair_type) :: auth
 
     ! setting username and password
-    auth = pair_type('user', 'passwd')   
-    res = request(url='https://httpbin.org/basic-auth/user/passwd', auth=auth)
+    auth = pair_type('postman', 'password')   
+    res = request(url='https://postman-echo.com/basic-auth', auth=auth)
 
     msg = 'test_auth: '
 
@@ -28,8 +28,8 @@ program test_auth
     end if
 
     ! Content Length Validation
-    if (res%content_length /= 47 .or. &
-        len(res%content) /= 47) then
+    if (res%content_length /= 27 .or. &
+        len(res%content) /= 27) then
         ok = .false.
         print '(a)', 'Failed : Content Length Validation'
     end if

test/test_timeout.f90

@@ -0,0 +1,34 @@
+program test_timeout
+    use iso_fortran_env, only: stderr => error_unit
+    use http, only : response_type, request
+ 
+    implicit none
+    type(response_type) :: res
+    character(:), allocatable :: msg
+    logical :: ok = .true.
+
+
+    res = request(url='https://httpbin.org/delay/10', timeout=1)
+    
+    msg = 'test_timeout: '
+
+    if(res%err_msg /= 'Timeout was reached') then
+        ok = .false.
+        print '(a)', 'Failed : Timeout not reached'
+    end if
+
+    ! Status Code Validation
+    if (res%status_code /= 0) then
+        ok = .false.
+        print '(a)', 'Failed : Status Code Validation'
+    end if
+
+    if (.not. ok) then 
+        msg = msg // 'Test Case Failed'
+        write(stderr, '(a)'), msg
+        error stop 1
+    else
+        msg = msg // 'All tests passed.'
+        print '(a)', msg 
+    end if
+end program test_timeout