path: root/resources/tools/presentation/input_data_parser.py

# Copyright (c) 2018 Cisco and/or its affiliates.
# Licensed 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.

"""Data pre-processing

- extract data from output.xml files generated by Jenkins jobs and store in
  pandas' Series,
- provide access to the data.
"""

import re
import pandas as pd
import logging
import xml.etree.ElementTree as ET

from robot.api import ExecutionResult, ResultVisitor
from robot import errors
from collections import OrderedDict
from string import replace


class ExecutionChecker(ResultVisitor):
    """Class to traverse through the test suite structure.

    The functionality implemented in this class generates a json structure:

    Performance tests:

    {
        "metadata": {  # Optional
            "version": "VPP version",
            "job": "Jenkins job name",
            "build": "Information about the build"
        },
        "suites": {
            "Suite name 1": {
                "doc": "Suite 1 documentation",
                "parent": "Suite 1 parent",
                "level": "Level of the suite in the suite hierarchy"
            }
            "Suite name N": {
                "doc": "Suite N documentation",
                "parent": "Suite 2 parent",
                "level": "Level of the suite in the suite hierarchy"
            }
        }
        "tests": {
            "ID": {
                "name": "Test name",
                "parent": "Name of the parent of the test",
                "doc": "Test documentation"
                "msg": "Test message"
                "tags": ["tag 1", "tag 2", "tag n"],
                "type": "PDR" | "NDR",
                "throughput": {
                    "value": int,
                    "unit": "pps" | "bps" | "percentage"
                },
                "latency": {
                    "direction1": {
                        "100": {
                            "min": int,
                            "avg": int,
                            "max": int
                        },
                        "50": {  # Only for NDR
                            "min": int,
                            "avg": int,
                            "max": int
                        },
                        "10": {  # Only for NDR
                            "min": int,
                            "avg": int,
                            "max": int
                        }
                    },
                    "direction2": {
                        "100": {
                            "min": int,
                            "avg": int,
                            "max": int
                        },
                        "50": {  # Only for NDR
                            "min": int,
                            "avg": int,
                            "max": int
                        },
                        "10": {  # Only for NDR
                            "min": int,
                            "avg": int,
                            "max": int
                        }
                    }
                },
                "lossTolerance": "lossTolerance",  # Only for PDR
                "vat-history": "DUT1 and DUT2 VAT History"
                },
                "show-run": "Show Run"
            },
            "ID" {
                # next test
            }
        }
    }

    Functional tests:


    {
        "metadata": {  # Optional
            "version": "VPP version",
            "job": "Jenkins job name",
            "build": "Information about the build"
        },
        "suites": {
            "Suite name 1": {
                "doc": "Suite 1 documentation",
                "parent": "Suite 1 parent",
                "level": "Level of the suite in the suite hierarchy"
            }
            "Suite name N": {
                "doc": "Suite N documentation",
                "parent": "Suite 2 parent",
                "level": "Level of the suite in the suite hierarchy"
            }
        }
        "tests": {
            "ID": {
                "name": "Test name",
                "parent": "Name of the parent of the test",
                "doc": "Test documentation"
                "msg": "Test message"
                "tags": ["tag 1", "tag 2", "tag n"],
                "vat-history": "DUT1 and DUT2 VAT History"
                "show-run": "Show Run"
                "status": "PASS" | "FAIL"
            },
            "ID" {
                # next test
            }
        }
    }

    .. note:: ID is the lowercase full path to the test.
    """

    REGEX_RATE = re.compile(r'^[\D\d]*FINAL_RATE:\s(\d+\.\d+)\s(\w+)')

    REGEX_LAT_NDR = re.compile(r'^[\D\d]*'
                               r'LAT_\d+%NDR:\s\[\'(-?\d+\/-?\d+/-?\d+)\','
                               r'\s\'(-?\d+/-?\d+/-?\d+)\'\]\s\n'
                               r'LAT_\d+%NDR:\s\[\'(-?\d+/-?\d+/-?\d+)\','
                               r'\s\'(-?\d+/-?\d+/-?\d+)\'\]\s\n'
                               r'LAT_\d+%NDR:\s\[\'(-?\d+/-?\d+/-?\d+)\','
                               r'\s\'(-?\d+/-?\d+/-?\d+)\'\]')

    REGEX_LAT_PDR = re.compile(r'^[\D\d]*'
                               r'LAT_\d+%PDR:\s\[\'(-?\d+/-?\d+/-?\d+)\','
                               r'\s\'(-?\d+/-?\d+/-?\d+)\'\][\D\d]*')

    REGEX_TOLERANCE = re.compile(r'^[\D\d]*LOSS_ACCEPTANCE:\s(\d*\.\d*)\s'
                                 r'[\D\d]*')

    REGEX_VERSION = re.compile(r"(stdout: 'vat# vat# Version:)(\s*)(.*)")

    REGEX_TCP = re.compile(r'Total\s(rps|cps|throughput):\s([0-9]*).*$')

    REGEX_MRR = re.compile(r'MaxReceivedRate_Results\s\[pkts/(\d*)sec\]:\s'
                           r'tx\s(\d*),\srx\s(\d*)')

    def __init__(self, **metadata):
        """Initialisation.

        :param metadata: Key-value pairs to be included in "metadata" part of
        JSON structure.
        :type metadata: dict
        """

        # Type of message to parse out from the test messages
        self._msg_type = None

        # VPP version
        self._version = None

        # Number of VAT History messages found:
        # 0 - no message
        # 1 - VAT History of DUT1
        # 2 - VAT History of DUT2
        self._lookup_kw_nr = 0
        self._vat_history_lookup_nr = 0

        # Number of Show Running messages found
        # 0 - no message
        # 1 - Show run message found
        self._show_run_lookup_nr = 0

        # Test ID of currently processed test- the lowercase full path to the
        # test
        self._test_ID = None

        # The main data structure
        self._data = {
            "metadata": OrderedDict(),
            "suites": OrderedDict(),
            "tests": OrderedDict()
        }

        # Save the provided metadata
        for key, val in metadata.items():
            self._data["metadata"][key] = val

        # Dictionary defining the methods used to parse different types of
        # messages
        self.parse_msg = {
            "setup-version": self._get_version,
            "teardown-vat-history": self._get_vat_history,
            "test-show-runtime": self._get_show_run
        }

    @property
    def data(self):
        """Getter - Data parsed from the XML file.

        :returns: Data parsed from the XML file.
        :rtype: dict
        """
        return self._data

    def _get_version(self, msg):
        """Called when extraction of VPP version is required.

        :param msg: Message to process.
        :type msg: Message
        :returns: Nothing.
        """

        if msg.message.count("stdout: 'vat# vat# Version:"):
            self._version = str(re.search(self.REGEX_VERSION, msg.message).
                                group(3))
            self._data["metadata"]["version"] = self._version
            self._msg_type = None

            logging.debug("    VPP version: {0}".format(self._version))

    def _get_vat_history(self, msg):
        """Called when extraction of VAT command history is required.

        :param msg: Message to process.
        :type msg: Message
        :returns: Nothing.
        """
        if msg.message.count("VAT command history:"):
            self._vat_history_lookup_nr += 1
            if self._vat_history_lookup_nr == 1:
                self._data["tests"][self._test_ID]["vat-history"] = str()
            else:
                self._msg_type = None
            text = re.sub("[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3} "
                          "VAT command history:", "", msg.message, count=1). \
                replace("\n\n", "\n").replace('\n', ' |br| ').\
                replace('\r', '').replace('"', "'")

            self._data["tests"][self._test_ID]["vat-history"] += " |br| "
            self._data["tests"][self._test_ID]["vat-history"] += \
                "**DUT" + str(self._vat_history_lookup_nr) + ":** " + text

    def _get_show_run(self, msg):
        """Called when extraction of VPP operational data (output of CLI command
        Show Runtime) is required.

        :param msg: Message to process.
        :type msg: Message
        :returns: Nothing.
        """
        if msg.message.count("return STDOUT Thread "):
            self._show_run_lookup_nr += 1
            if self._lookup_kw_nr == 1 and self._show_run_lookup_nr == 1:
                self._data["tests"][self._test_ID]["show-run"] = str()
            if self._lookup_kw_nr > 1:
                self._msg_type = None
            if self._show_run_lookup_nr == 1:
                text = msg.message.replace("vat# ", "").\
                    replace("return STDOUT ", "").replace("\n\n", "\n").\
                    replace('\n', ' |br| ').\
                    replace('\r', '').replace('"', "'")
                try:
                    self._data["tests"][self._test_ID]["show-run"] += " |br| "
                    self._data["tests"][self._test_ID]["show-run"] += \
                        "**DUT" + str(self._lookup_kw_nr) + ":** |br| " + text
                except KeyError:
                    pass

    def _get_latency(self, msg, test_type):
        """Get the latency data from the test message.

        :param msg: Message to be parsed.
        :param test_type: Type of the test - NDR or PDR.
        :type msg: str
        :type test_type: str
        :returns: Latencies parsed from the message.
        :rtype: dict
        """

        if test_type == "NDR":
            groups = re.search(self.REGEX_LAT_NDR, msg)
            groups_range = range(1, 7)
        elif test_type == "PDR":
            groups = re.search(self.REGEX_LAT_PDR, msg)
            groups_range = range(1, 3)
        else:
            return {}

        latencies = list()
        for idx in groups_range:
            try:
                lat = [int(item) for item in str(groups.group(idx)).split('/')]
            except (AttributeError, ValueError):
                lat = [-1, -1, -1]
            latencies.append(lat)

        keys = ("min", "avg", "max")
        latency = {
            "direction1": {
            },
            "direction2": {
            }
        }

        latency["direction1"]["100"] = dict(zip(keys, latencies[0]))
        latency["direction2"]["100"] = dict(zip(keys, latencies[1]))
        if test_type == "NDR":
            latency["direction1"]["50"] = dict(zip(keys, latencies[2]))
            latency["direction2"]["50"] = dict(zip(keys, latencies[3]))
            latency["direction1"]["10"] = dict(zip(keys, latencies[4]))
            latency["direction2"]["10"] = dict(zip(keys, latencies[5]))

        return latency

    def visit_suite(self, suite):
        """Implements traversing through the suite and its direct children.

        :param suite: Suite to process.
        :type suite: Suite
        :returns: Nothing.
        """
        if self.start_suite(suite) is not False:
            suite.suites.visit(self)
            suite.tests.visit(self)
            self.end_suite(suite)

    def start_suite(self, suite):
        """Called when suite starts.

        :param suite: Suite to process.
        :type suite: Suite
        :returns: Nothing.
        """

        try:
            parent_name = suite.parent.name
        except AttributeError:
            return

        doc_str = suite.doc.replace('"', "'").replace('\n', ' ').\
            replace('\r', '').replace('*[', ' |br| *[').replace("*", "**")
        doc_str = replace(doc_str, ' |br| *[', '*[', maxreplace=1)

        self._data["suites"][suite.longname.lower().replace('"', "'").
            replace(" ", "_")] = {
                "name": suite.name.lower(),
                "doc": doc_str,
                "parent": parent_name,
                "level": len(suite.longname.split("."))
            }

        suite.keywords.visit(self)

    def end_suite(self, suite):
        """Called when suite ends.

        :param suite: Suite to process.
        :type suite: Suite
        :returns: Nothing.
        """
        pass

    def visit_test(self, test):
        """Implements traversing through the test.

        :param test: Test to process.
        :type test: Test
        :returns: Nothing.
        """
        if self.start_test(test) is not False:
            test.keywords.visit(self)
            self.end_test(test)

    def start_test(self, test):
        """Called when test starts.

        :param test: Test to process.
        :type test: Test
        :returns: Nothing.
        """

        tags = [str(tag) for tag in test.tags]
        test_result = dict()
        test_result["name"] = test.name.lower()
        test_result["parent"] = test.parent.name.lower()
        test_result["tags"] = tags
        doc_str = test.doc.replace('"', "'").replace('\n', ' '). \
            replace('\r', '').replace('[', ' |br| [')
        test_result["doc"] = replace(doc_str, ' |br| [', '[', maxreplace=1)
        test_result["msg"] = test.message.replace('\n', ' |br| '). \
            replace('\r', '').replace('"', "'")
        if test.status == "PASS" and ("NDRPDRDISC" in tags or
                                      "TCP" in tags or
                                      "MRR" in tags):
            if "NDRDISC" in tags:
                test_type = "NDR"
            elif "PDRDISC" in tags:
                test_type = "PDR"
            elif "TCP" in tags:
                test_type = "TCP"
            elif "MRR" in tags:
                test_type = "MRR"
            else:
                return

            test_result["type"] = test_type

            if test_type in ("NDR", "PDR"):
                try:
                    rate_value = str(re.search(
                        self.REGEX_RATE, test.message).group(1))
                except AttributeError:
                    rate_value = "-1"
                try:
                    rate_unit = str(re.search(
                        self.REGEX_RATE, test.message).group(2))
                except AttributeError:
                    rate_unit = "-1"

                test_result["throughput"] = dict()
                test_result["throughput"]["value"] = \
                    int(rate_value.split('.')[0])
                test_result["throughput"]["unit"] = rate_unit
                test_result["latency"] = \
                    self._get_latency(test.message, test_type)
                if test_type == "PDR":
                    test_result["lossTolerance"] = str(re.search(
                        self.REGEX_TOLERANCE, test.message).group(1))

            elif test_type in ("TCP", ):
                groups = re.search(self.REGEX_TCP, test.message)
                test_result["result"] = dict()
                test_result["result"]["value"] = int(groups.group(2))
                test_result["result"]["unit"] = groups.group(1)
            elif test_type in ("MRR", ):
                groups = re.search(self.REGEX_MRR, test.message)
                test_result["result"] = dict()
                test_result["result"]["duration"] = int(groups.group(1))
                test_result["result"]["tx"] = int(groups.group(2))
                test_result["result"]["rx"] = int(groups.group(3))
                test_result["result"]["throughput"] = int(
                    test_result["result"]["rx"] /
                    test_result["result"]["duration"])
        else:
            test_result["status"] = test.status

        self._test_ID = test.longname.lower()
        self._data["tests"][self._test_ID] = test_result

    def end_test(self, test):
        """Called when test ends.

        :param test: Test to process.
        :type test: Test
        :returns: Nothing.
        """
        pass

    def visit_keyword(self, keyword):
        """Implements traversing through the keyword and its child keywords.

        :param keyword: Keyword to process.
        :type keyword: Keyword
        :returns: Nothing.
        """
        if self.start_keyword(keyword) is not False:
            self.end_keyword(keyword)

    def start_keyword(self, keyword):
        """Called when keyword starts. Default implementation does nothing.

        :param keyword: Keyword to process.
        :type keyword: Keyword
        :returns: Nothing.
        """
        try:
            if keyword.type == "setup":
                self.visit_setup_kw(keyword)
            elif keyword.type == "teardown":
                self._lookup_kw_nr = 0
                self.visit_teardown_kw(keyword)
            else:
                self._lookup_kw_nr = 0
                self.visit_test_kw(keyword)
        except AttributeError:
            pass

    def end_keyword(self, keyword):
        """Called when keyword ends. Default implementation does nothing.

        :param keyword: Keyword to process.
        :type keyword: Keyword
        :returns: Nothing.
        """
        pass

    def visit_test_kw(self, test_kw):
        """Implements traversing through the test keyword and its child
        keywords.

        :param test_kw: Keyword to process.
        :type test_kw: Keyword
        :returns: Nothing.
        """
        for keyword in test_kw.keywords:
            if self.start_test_kw(keyword) is not False:
                self.visit_test_kw(keyword)
                self.end_test_kw(keyword)

    def start_test_kw(self, test_kw):
        """Called when test keyword starts. Default implementation does
        nothing.

        :param test_kw: Keyword to process.
        :type test_kw: Keyword
        :returns: Nothing.
        """
        if test_kw.name.count("Show Runtime Counters On All Duts"):
            self._lookup_kw_nr += 1
            self._show_run_lookup_nr = 0
            self._msg_type = "test-show-runtime"
            test_kw.messages.visit(self)

    def end_test_kw(self, test_kw):
        """Called when keyword ends. Default implementation does nothing.

        :param test_kw: Keyword to process.
        :type test_kw: Keyword
        :returns: Nothing.
        """
        pass

    def visit_setup_kw(self, setup_kw):
        """Implements traversing through the teardown keyword and its child
        keywords.

        :param setup_kw: Keyword to process.
        :type setup_kw: Keyword
        :returns: Nothing.
        """
        for keyword in setup_kw.keywords:
            if self.start_setup_kw(keyword) is not False:
                self.visit_setup_kw(keyword)
                self.end_setup_kw(keyword)

    def start_setup_kw(self, setup_kw):
        """Called when teardown keyword starts. Default implementation does
        nothing.

        :param setup_kw: Keyword to process.
        :type setup_kw: Keyword
        :returns: Nothing.
        """
        if setup_kw.name.count("Vpp Show Version Verbose") \
                and not self._version:
            self._msg_type = "setup-version"
            setup_kw.messages.visit(self)

    def end_setup_kw(self, setup_kw):
        """Called when keyword ends. Default implementation does nothing.

        :param setup_kw: Keyword to process.
        :type setup_kw: Keyword
        :returns: Nothing.
        """
        pass

    def visit_teardown_kw(self, teardown_kw):
        """Implements traversing through the teardown keyword and its child
        keywords.

        :param teardown_kw: Keyword to process.
        :type teardown_kw: Keyword
        :returns: Nothing.
        """
        for keyword in teardown_kw.keywords:
            if self.start_teardown_kw(keyword) is not False:
                self.visit_teardown_kw(keyword)
                self.end_teardown_kw(keyword)

    def start_teardown_kw(self, teardown_kw):
        """Called when teardown keyword starts. Default implementation does
        nothing.

        :param teardown_kw: Keyword to process.
        :type teardown_kw: Keyword
        :returns: Nothing.
        """

        if teardown_kw.name.count("Show Vat History On All Duts"):
            self._vat_history_lookup_nr = 0
            self._msg_type = "teardown-vat-history"
            teardown_kw.messages.visit(self)

    def end_teardown_kw(self, teardown_kw):
        """Called when keyword ends. Default implementation does nothing.

        :param teardown_kw: Keyword to process.
        :type teardown_kw: Keyword
        :returns: Nothing.
        """
        pass

    def visit_message(self, msg):
        """Implements visiting the message.

        :param msg: Message to process.
        :type msg: Message
        :returns: Nothing.
        """
        if self.start_message(msg) is not False:
            self.end_message(msg)

    def start_message(self, msg):
        """Called when message starts. Get required information from messages:
        - VPP version.

        :param msg: Message to process.
        :type msg: Message
        :returns: Nothing.
        """

        if self._msg_type:
            self.parse_msg[self._msg_type](msg)

    def end_message(self, msg):
        """Called when message ends. Default implementation does nothing.

        :param msg: Message to process.
        :type msg: Message
        :returns: Nothing.
        """
        pass


class InputData(object):
    """Input data

    The data is extracted from output.xml files generated by Jenkins jobs and
    stored in pandas' DataFrames.

    The data structure:
    - job name
      - build number
        - metadata
          - job
          - build
          - vpp version
        - suites
        - tests
          - ID: test data (as described in ExecutionChecker documentation)
    """

    def __init__(self, spec):
        """Initialization.

        :param spec: Specification.
        :type spec: Specification
        """

        # Specification:
        self._cfg = spec

        # Data store:
        self._input_data = None

    @property
    def data(self):
        """Getter - Input data.

        :returns: Input data
        :rtype: pandas.Series
        """
        return self._input_data

    def metadata(self, job, build):
        """Getter - metadata

        :param job: Job which metadata we want.
        :param build: Build which metadata we want.
        :type job: str
        :type build: str
        :returns: Metadata
        :rtype: pandas.Series
        """

        return self.data[job][build]["metadata"]

    def suites(self, job, build):
        """Getter - suites

        :param job: Job which suites we want.
        :param build: Build which suites we want.
        :type job: str
        :type build: str
        :returns: Suites.
        :rtype: pandas.Series
        """

        return self.data[job][str(build)]["suites"]

    def tests(self, job, build):
        """Getter - tests

        :param job: Job which tests we want.
        :param build: Build which tests we want.
        :type job: str
        :type build: str
        :returns: Tests.
        :rtype: pandas.Series
        """

        return self.data[job][build]["tests"]

    @staticmethod
    def _parse_tests(job, build):
        """Process data from robot output.xml file and return JSON structured
        data.

        :param job: The name of job which build output data will be processed.
        :param build: The build which output data will be processed.
        :type job: str
        :type build: dict
        :returns: JSON data structure.
        :rtype: dict
        """

        tree = ET.parse(build["file-name"])
        root = tree.getroot()
        generated = root.attrib["generated"]

        with open(build["file-name"], 'r') as data_file:
            try:
                result = ExecutionResult(data_file)
            except errors.DataError as err:
                logging.error("Error occurred while parsing output.xml: {0}".
                              format(err))
                return None
        checker = ExecutionChecker(job=job, build=build, generated=generated)
        result.visit(checker)

        return checker.data

    def read_data(self):
        """Parse input data from input files and store in pandas' Series.
        """

        logging.info("Parsing input files ...")

        job_data = dict()
        for job, builds in self._cfg.builds.items():
            logging.info("  Extracting data from the job '{0}' ...'".
                         format(job))
            builds_data = dict()
            for build in builds:
                if build["status"] == "failed" \
                        or build["status"] == "not found":
                    continue
                logging.info("    Extracting data from the build '{0}'".
                             format(build["build"]))
                logging.info("    Processing the file '{0}'".
                             format(build["file-name"]))
                data = InputData._parse_tests(job, build)
                if data is None:
                    logging.error("Input data file from the job '{job}', build "
                                  "'{build}' is damaged. Skipped.".
                                  format(job=job, build=build["build"]))
                    continue

                build_data = pd.Series({
                    "metadata": pd.Series(data["metadata"].values(),
                                          index=data["metadata"].keys()),
                    "suites": pd.Series(data["suites"].values(),
                                        index=data["suites"].keys()),
                    "tests": pd.Series(data["tests"].values(),
                                       index=data["tests"].keys()),
                    })
                builds_data[str(build["build"])] = build_data
                logging.info("    Done.")

            job_data[job] = pd.Series(builds_data.values(),
                                      index=builds_data.keys())
            logging.info("  Done.")

        self._input_data = pd.Series(job_data.values(), index=job_data.keys())
        logging.info("Done.")

    @staticmethod
    def _end_of_tag(tag_filter, start=0, closer="'"):
        """Return the index of character in the string which is the end of tag.

        :param tag_filter: The string where the end of tag is being searched.
        :param start: The index where the searching is stated.
        :param closer: The character which is the tag closer.
        :type tag_filter: str
        :type start: int
        :type closer: str
        :returns: The index of the tag closer.
        :rtype: int
        """

        try:
            idx_opener = tag_filter.index(closer, start)
            return tag_filter.index(closer, idx_opener + 1)
        except ValueError:
            return None

    @staticmethod
    def _condition(tag_filter):
        """Create a conditional statement from the given tag filter.

        :param tag_filter: Filter based on tags from the element specification.
        :type tag_filter: str
        :returns: Conditional statement which can be evaluated.
        :rtype: str
        """

        index = 0
        while True:
            index = InputData._end_of_tag(tag_filter, index)
            if index is None:
                return tag_filter
            index += 1
            tag_filter = tag_filter[:index] + " in tags" + tag_filter[index:]

    def filter_data(self, element, params=None, data_set="tests",
                    continue_on_error=False):
        """Filter required data from the given jobs and builds.

        The output data structure is:

        - job 1
          - build 1
            - test (suite) 1 ID:
              - param 1
              - param 2
              ...
              - param n
            ...
            - test (suite) n ID:
            ...
          ...
          - build n
        ...
        - job n

        :param element: Element which will use the filtered data.
        :param params: Parameters which will be included in the output. If None,
        all parameters are included.
        :param data_set: The set of data to be filtered: tests, suites,
        metadata.
        :param continue_on_error: Continue if there is error while reading the
        data. The Item will be empty then
        :type element: pandas.Series
        :type params: list
        :type data_set: str
        :type continue_on_error: bool
        :returns: Filtered data.
        :rtype pandas.Series
        """

        logging.info("    Creating the data set for the {0} '{1}'.".
                     format(element.get("type", ""), element.get("title", "")))

        try:
            if element["filter"] in ("all", "template"):
                cond = "True"
            else:
                cond = InputData._condition(element["filter"])
            logging.debug("   Filter: {0}".format(cond))
        except KeyError:
            logging.error("  No filter defined.")
            return None

        if params is None:
            params = element.get("parameters", None)

        data = pd.Series()
        try:
            for job, builds in element["data"].items():
                data[job] = pd.Series()
                for build in builds:
                    data[job][str(build)] = pd.Series()
                    try:
                        data_iter = self.data[job][str(build)][data_set].\
                            iteritems()
                    except KeyError:
                        if continue_on_error:
                            continue
                        else:
                            return None
                    for test_ID, test_data in data_iter:
                        if eval(cond, {"tags": test_data.get("tags", "")}):
                            data[job][str(build)][test_ID] = pd.Series()
                            if params is None:
                                for param, val in test_data.items():
                                    data[job][str(build)][test_ID][param] = val
                            else:
                                for param in params:
                                    try:
                                        data[job][str(build)][test_ID][param] =\
                                            test_data[param]
                                    except KeyError:
                                        data[job][str(build)][test_ID][param] =\
                                            "No Data"
            return data

        except (KeyError, IndexError, ValueError) as err:
            logging.error("   Missing mandatory parameter in the element "
                          "specification: {0}".format(err))
            return None
        except AttributeError:
            return None
        except SyntaxError:
            logging.error("   The filter '{0}' is not correct. Check if all "
                          "tags are enclosed by apostrophes.".format(cond))
            return None

    @staticmethod
    def merge_data(data):
        """Merge data from more jobs and builds to a simple data structure.

        The output data structure is:

        - test (suite) 1 ID:
          - param 1
          - param 2
          ...
          - param n
        ...
        - test (suite) n ID:
        ...

        :param data: Data to merge.
        :type data: pandas.Series
        :returns: Merged data.
        :rtype: pandas.Series
        """

        logging.info("    Merging data ...")

        merged_data = pd.Series()
        for _, builds in data.iteritems():
            for _, item in builds.iteritems():
                for ID, item_data in item.iteritems():
                    merged_data[ID] = item_data

        return merged_data