tbx/include/utils/sequencer.h

445 lines
18 KiB
C++

/*!
* \file utils/sequencer.h
* \brief
* A terminal-like device communication automation tool
*
* \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
*
* <dl class=\"section copyright\"><dt>License</dt><dd>
* The MIT License (MIT)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
* </dd></dl>
*/
#ifndef TBX_UTILS_SEQUENCER_H_
#define TBX_UTILS_SEQUENCER_H_
#include <core/core.h>
#include <core/crtp.h>
#include <cont/range.h>
#include <ctime>
#include <array>
#include <string_view>
#include <limits>
#include <type_traits>
#include <functional>
namespace tbx {
/*!
* \class sequencer
* \brief
* A CRTP base class to provide the sequencer functionality.
*
* Sequencer can automate communication with a terminal-like device such as AT-command modems etc...
* It can operate based on a script array and handle the outgoing commands and incoming responses.
* The user can create matching rules on received data and hook handlers and actions on them.
*
* The derived class (implementation) has to provide:
* 1) size_t get(Data_t* data);
* This function return 0 or a number of Data_t items. The data points to buffer for the input data.
* 2) size_t put(const Data_t* data, size_t n);
* This function sends to implementation the data pointed by \c data witch have size \c n.
* 3) clock_t clock();
* This function return a number to be used as time. The units of this function may be arbitrary but they
* match the units in \c record_t::timeout field.
*
* \tparam Impl_t The type of derived class
* \tparam Cont_t The container type holding the data of type \c Data_t for the derived class.
* \tparam Data_t The char-like stream item type. Usually \c char
* \tparam N The size of the sequence buffer to temporary store each line from get().
*
* \note
* We need access to derived class container to sneaky get a range of the data beside
* the normal data flow, in order to implement the \see control_t::DETECT operation.
*/
template <typename Impl_t, typename Cont_t, typename Data_t, size_t N>
class sequencer {
_CRTP_IMPL(Impl_t);
static_assert(
std::is_same_v<typename Cont_t::value_type, Data_t>,
"Cont_t must be a container of type Data_t"
);
// local type dispatch
using str_view_t = std::basic_string_view<Data_t>;
using range_t = typename Cont_t::range_t;
//! \name Public types
//! @{
public:
//! \enum status_t
//! \brief The sequencer run status
enum class status_t {
OK, ERROR
};
//! \enum action_t
//! \brief Possible response actions for the sequencer
enum class action_t {
NO, NEXT, GOTO, EXIT_OK, EXIT_ERROR
};
//! \enum control_t
//! \brief The control type of the script entry.
enum class control_t {
NOP, //!< No command, dont send or expect anything, used for delays
SEND, //!< Send data to implementation through put()
EXPECT, //!< Expects data from implementation via get()
DETECT //!< Detects data into rx buffer without receiving them via contents()
//! \note
//! The \c DETECT extra incoming channel serve the purpose of sneak into receive
//! buffer and check for data without getting them. This is useful when the receive driver
//! is buffered with a delimiter and we seek for data that don't follow the delimiter pattern.
//!
//! For example:
//! A modem sends reponses with '\n' termination but for some "special" command it opens a cursor
//! lets say ">$ " without '\n' at the end.
};
//! \enum match_t
//! \brief Token match types
enum class match_t {
NO, STARTS_WITH, ENDS_WITH, CONTAINS, nSTARTS_WITH, nENDS_WITH, nCONTAINS
};
/*!
* Match handler function pointer type.
* Expects a pointer to buffer and a size and returns status
*/
using handler_ft = void (*) (const Data_t*, size_t);
/*!
* \struct handle_t
* \brief
* The script record handle block.
*
* Each script record contains some blocks for matching functionality. Each block
* has a token and a matching type. If the response matches the token, the sequencer calls
* the handler and perform the action.
*/
struct handle_t {
std::basic_string_view<Data_t>
token; //!< The token for the match
match_t match_type; //!< The matching type functionality
handler_ft handler; //!< The handler to called if the match is successful.
action_t action; //!< The action to be performer if the match is successful
size_t idx; //!< The index for the action_t::GOTO action. Otherwise can be left 0.
};
/*!
* \struct record_t
* \brief
* Describes the sequencer's script record entry (line).
*
* Each line consist from a control, 2 blocks and a timeout. The control says if we send or receive data.
* The blocks contain the data and the matching information. And the timeout guards the entire line.
*/
template<size_t Nhandles =2>
struct record_t {
control_t control; //!< The type of the entry
std::array<handle_t, Nhandles>
block; //!< The matching blocks
clock_t timeout; //!< Timeout in CPU time
};
/*!
* \struct script_t
* \brief
* Describes the sequencer's script.
*
* The user can create arrays as the example bellow to act as a script.
* \code
* const std::array<Seq::record_t, 8> script = {{
* / * 0 * / {Seq::control_t::NOP, {"", Seq::match_t::NO, nullptr, Seq::action_t::GOTO, 1}, 1000}, //delay 1000 clocks
* / * 1 * / {Seq::control_t::SEND, {"ATE0\r\n", Seq::match_t::NO, nullptr, Seq::action_t::NEXT, 0}, 1000},
* / * 2 * / {Seq::control_t::EXPECT, {{
* {"OK\r\n", Seq::match_t::ENDS_WITH, nullptr, Seq::action_t::NEXT, 0},
* {"ERROR", Seq::match_t::CONTAINS, nullptr, Seq::action_t::EXIT_ERROR, 0} }},
* 1000
* },
* // ...
* }};
* \endcode
*/
template <size_t Nrecords, size_t Nhandles =2>
using script_t = std::array<record_t<Nhandles>, Nrecords>;
//! @}
//! \name Constructor / Destructor
//!@{
protected:
~sequencer () = default; //!< \brief Allow destructor from derived only
sequencer () = default; //!< \brief A default constructor from derived only
sequencer(const sequencer&) = delete; //!< No copies
sequencer& operator= (const sequencer&) = delete; //!< No copy assignments
//!@}
//! \name Sequencer interface requirements for implementer
//! @{
private:
size_t get_ (Data_t* data) { return impl().get (data); }
size_t put_ (const Data_t* data, size_t n) { return impl().put (data, n); }
const range_t contents_ () const { return impl().contents(); }
clock_t clock_ () { return impl().clock(); }
//! @}
//! \name Private functionality
//! @{
private:
/*!
* \brief
* Check if the \c stream starts with the \c prefix
* \param stream The stream in witch we search
* \param prefix What we search
* \return True on success, false otherwise
*/
static bool starts_with_ (const str_view_t stream, const str_view_t prefix) {
return (stream.rfind(prefix, 0) != str_view_t::npos);
}
/*!
* \brief
* Check if the \c stream ends with the \c postfix
* \param stream The stream in witch we search
* \param postfix What we search
* \return True on success, false otherwise
*/
static bool ends_with_ (const str_view_t stream, const str_view_t postfix) {
if (stream.size() < postfix.size())
return false;
return (
stream.compare(
stream.size() - postfix.size(),
postfix.size(),
postfix) == 0
);
}
/*!
* \brief
* Check if the \c haystack contains the \c needle
* \param haystack The stream in witch we search
* \param needle What we search
* \return True on success, false otherwise
*/
static bool contains_ (const str_view_t haystack, const str_view_t needle) {
return (haystack.find(needle) != str_view_t::npos);
}
/*!
* \brief
* Return the new sequencer's step value.
*
* Step is index to the sequencer's script array.
*
* \param current_idx The current step value
* \param action The advancing type
* \param go_idx The new value of the step in the case of GOTO type
* \return The new sequencer's step value
*/
static size_t step_ (size_t current_idx, action_t action, size_t go_idx =0) {
switch (action) {
default:
case action_t::NO: return current_idx;
case action_t::NEXT: return ++current_idx;
case action_t::GOTO: return go_idx;
case action_t::EXIT_OK:
case action_t::EXIT_ERROR:
return 0;
}
}
static status_t action_ (size_t& step, const handle_t& block, const str_view_t buffer = str_view_t{}) {
if (block.handler != nullptr)
block.handler(buffer.begin(), buffer.size());
switch (block.action) {
case action_t::EXIT_OK:
step = std::numeric_limits<size_t>::max();
return status_t::OK;
case action_t::EXIT_ERROR:
step = std::numeric_limits<size_t>::max();
return status_t::ERROR;
default:
step = step_(step, block.action, block.idx);
return status_t::OK;
}
}
//! @}
public:
/*!
* \brief
* Checks if the \c needle matches the \c haystack.
*
* \param type The type of matching functionality
* \param haystack The stream in witch we search
* \param needle The stream we search
* \return True on match
*/
static bool match (const str_view_t haystack, const str_view_t needle, match_t type) {
switch (type) {
default:
case match_t::NO: return true;
case match_t::STARTS_WITH: return starts_with_(haystack, needle);
case match_t::ENDS_WITH: return ends_with_(haystack, needle);
case match_t::CONTAINS: return contains_(haystack, needle);
case match_t::nSTARTS_WITH: return !starts_with_(haystack, needle);
case match_t::nENDS_WITH: return !ends_with_(haystack, needle);
case match_t::nCONTAINS: return !contains_(haystack, needle);
}
}
/*!
* \brief
* A static functionality to provide access to sequencer's inner matching mechanism.
* Checks the \c buffer against \c handle and calls its action if needed.
*
* \param handle Reference to handle
* \param buffer The buffer to check
* \return True on match, false otherwise
*/
static bool check_handle (const handle_t& handle, const str_view_t buffer) {
size_t tmp{};
if (match(buffer, handle.token, handle.match_type)) {
action_ (tmp, handle, buffer);
return true;
}
return false;
}
/*!
* \brief
* Run the script array
*
* The main sequencer functionality. It starts with the first entry of the array.
* - If the entry is \c NOP it executes the action after the timeout.
* \c token and \c handler are discarded.
* - If the entry is \c SEND it uses the first handle block's token to send and executes the action after that.
* \c timeout is discarded.
* - If the entry is \c EXCEPTS it continuously try to receive data using implementation's get until one
* of the handle blocks match.
* On match:
* - Calls the handler if there is one
* - Executes the action
* - Skips the next handle blocks if there is any.
* If there is no match on timeout it return status_t::EXIT_ERROR
* - If the entry is \c DETECT it continuously try to detect data using implementation's contents until one
* of the handle blocks match.
* On match:
* - Calls the handler if there is one
* - Executes the action
* - Skips the next handle blocks if there is any.
* If there is no match on timeout it return status_t::EXIT_ERROR
*
* \tparam Steps The number of steps of the script
* \tparam Nhandles The number of handle blocks in the each script record.
*
* \param script Reference to script to run
* \return The status of entire operation as described above
*/
template <size_t Steps, size_t Nhandles>
bool run (const script_t<Steps, Nhandles>& script) {
Data_t buffer[N];
size_t resp_size{};
status_t status{};
clock_t mark = clock_();
for (size_t step =0, p_step =0 ; step < Steps ; ) {
const record_t<Nhandles>& it = script[step];
if (step != p_step) {
p_step = step;
mark = clock_();
}
switch (it.control) {
default:
case control_t::NOP:
if ((clock_() - mark) >= it.timeout)
status = action_ (step, it.block[0]);
break;
case control_t::SEND:
if (put_(it.block[0].token.data(), it.block[0].token.size()) != it.block[0].token.size())
return false;
status = action_ (step, it.block[0]);
break;
case control_t::EXPECT:
resp_size = get_(buffer);
if (resp_size) {
for (auto& block : it.block) {
if (match(
{buffer, resp_size},
block.token,
block.match_type)) {
status = action_ (step, block, {buffer, resp_size});
break;
}
}
}
if (it.timeout && (clock_() - mark) >= it.timeout)
return false;
break;
case control_t::DETECT:
auto data = contents_();
if (data.begin() != data.end()) {
for (auto& block : it.block) {
if (match(
{data.begin(), static_cast<size_t>(data.end() - data.begin())},
block.token,
block.match_type)) {
status = action_ (step, block, {buffer, resp_size});
break;
}
}
}
if (it.timeout && (clock_() - mark) >= it.timeout)
return false;
break;
} // switch (it.control)
}
return (status == status_t::OK);
}
};
/*!
* An "empty" block for convenience.
*/
template <typename Impl_t, typename Cont_t, typename Data_t, size_t N>
constexpr typename sequencer<Impl_t, Cont_t, Data_t, N>::handle_t Sequencer_null_block = {
"",
sequencer<Impl_t, Cont_t, Data_t, N>::match_t::NO,
nullptr,
sequencer<Impl_t, Cont_t, Data_t, N>::action_t::NO,
0
};
}
#endif /* TBX_UTILS_SEQUENCER_H_ */