De-duplicate dependency tree calculations and data structures, de-clutter notebook

latency_graph/latency_graph_plots.py

@@ -0,0 +1,201 @@
+import math
+import re
+
+import graphviz as gv
+
+import latency_graph.latency_graph_structure as lg
+from matching.subscriptions import sanitize
+from tracing_interop.tr_types import TrContext
+
+NODE_COLORS = {
+        "sensing": {"fill": "#e1d5e7", "stroke": "#9673a6"},
+        "localization": {"fill": "#dae8fc", "stroke": "#6c8ebf"},
+        "perception": {"fill": "#d5e8d4", "stroke": "#82b366"},
+        "planning": {"fill": "#fff2cc", "stroke": "#d6b656"},
+        "control": {"fill": "#ffe6cc", "stroke": "#d79b00"},
+        "system": {"fill": "#f8cecc", "stroke": "#b85450"},
+        "vehicle_interface": {"fill": "#b0e3e6", "stroke": "#0e8088"},
+        None: {"fill": "#f5f5f5", "stroke": "#666666"}
+}
+
+NODE_NAMESPACE_MAPPING = {
+        'perception': 'perception',
+        'sensing': 'sensing',
+        'planning': 'planning',
+        'control': 'control',
+        'awapi': 'system',
+        'autoware_api': 'system',
+        'map': 'system',
+        'system': 'system',
+        'localization': 'localization',
+        'robot_state_publisher': None,
+        'aggregator_node': None,
+        'pointcloud_container': 'sensing',
+}
+
+
+def plot_latency_graph_full(lat_graph: lg.LatencyGraph, tr: TrContext, filename: str):
+    # Compare with: https://autowarefoundation.github.io/autoware-documentation/main/design/autoware-architecture/node-diagram/
+
+    g = gv.Digraph('G', filename="latency_graph.gv",
+                   node_attr={'shape': 'plain'},
+                   graph_attr={'pack': '1'})
+    g.graph_attr['rankdir'] = 'LR'
+
+    def plot_hierarchy(gv_parent, lg_node: lg.LGHierarchyLevel, **subgraph_kwargs):
+        if lg_node.name == "[NONE]":
+            return
+
+        print(f"{'  ' * lg_node.full_name.count('/')}Processing {lg_node.name}: {len(lg_node.callbacks)}")
+        with gv_parent.subgraph(name=f"cluster_{lg_node.full_name.replace('/', '__')}", **subgraph_kwargs) as c:
+            c.attr(label=lg_node.name)
+            for cb in lg_node.callbacks:
+                if isinstance(cb, lg.LGTrCallback):
+                    tr_cb = cb.cb
+                    try:
+                        sym = tr.callback_symbols.by_id.get(tr_cb.callback_object)
+                        pretty_sym = repr(sanitize(sym.symbol))
+                    except KeyError:
+                        pretty_sym = cb.name
+                    except TypeError:
+                        pretty_sym = cb.name
+                else:
+                    pretty_sym = cb.name
+
+                pretty_sym = pretty_sym.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
+
+                c.node(cb.id(),
+                       f'<<table BORDER="0" CELLBORDER="1" CELLSPACING="0"><tr><td port="in"></td><td>{pretty_sym}</td><td port="out"></td></tr></table>>')
+
+            for ch in lg_node.children:
+                plot_hierarchy(c, ch, **subgraph_kwargs)
+
+    def plot_lg(graph: lg.LatencyGraph):
+        for top_level_node in graph.top_node.children:
+            colors = NODE_COLORS[NODE_NAMESPACE_MAPPING.get(top_level_node.name)]
+            plot_hierarchy(g, top_level_node, graph_attr={'bgcolor': colors["fill"], 'pencolor': colors["stroke"]})
+
+        for edge in graph.edges:
+            g.edge(f"{edge.start.id()}:out", f"{edge.end.id()}:in")
+
+    plot_lg(lat_graph)
+
+    g.save(f"{filename}.gv")
+    g.render(f"{filename}.svg")
+
+    return g
+
+
+def plot_latency_graph_overview(lat_graph: lg.LatencyGraph, excl_node_patterns, input_node_patterns,
+                                output_node_patterns, max_hier_level, filename):
+    ##################################################
+    # Compute in/out topics for hierarchy level X
+    ##################################################
+
+    def get_nodes_on_level(lat_graph: lg.LatencyGraph):
+        def _traverse_node(node: lg.LGHierarchyLevel, cur_lvl=0):
+            if cur_lvl == max_hier_level:
+                return [node]
+
+            if not node.children:
+                return [node]
+
+            collected_nodes = []
+            for ch in node.children:
+                collected_nodes += _traverse_node(ch, cur_lvl + 1)
+            return collected_nodes
+
+        return _traverse_node(lat_graph.top_node)
+
+    lvl_nodes = get_nodes_on_level(lat_graph)
+    lvl_nodes = [n for n in lvl_nodes if not any(re.search(p, n.full_name) for p in excl_node_patterns)]
+
+    input_nodes = [n.full_name for n in lvl_nodes if any(re.search(p, n.full_name) for p in input_node_patterns)]
+    output_nodes = [n.full_name for n in lvl_nodes if any(re.search(p, n.full_name) for p in output_node_patterns)]
+
+    print(', '.join(map(lambda n: n, input_nodes)))
+    print(', '.join(map(lambda n: n, output_nodes)))
+    print(', '.join(map(lambda n: n.full_name, lvl_nodes)))
+
+    def _collect_callbacks(n: lg.LGHierarchyLevel):
+        callbacks = []
+        callbacks += n.callbacks
+        for ch in n.children:
+            callbacks += _collect_callbacks(ch)
+        return callbacks
+
+    cb_to_node_map = {}
+    for n in lvl_nodes:
+        cbs = _collect_callbacks(n)
+        for cb in cbs:
+            cb_to_node_map[cb.id()] = n
+
+    edges_between_nodes = {}
+    for edge in lat_graph.edges:
+        from_node = cb_to_node_map.get(edge.start.id())
+        to_node = cb_to_node_map.get(edge.end.id())
+
+        if from_node is None or to_node is None:
+            continue
+
+        if from_node.full_name == to_node.full_name:
+            continue
+
+        k = (from_node.full_name, to_node.full_name)
+
+        if k not in edges_between_nodes:
+            edges_between_nodes[k] = []
+
+        edges_between_nodes[k].append(edge)
+
+    g = gv.Digraph('G', filename="latency_graph.gv",
+                   node_attr={'shape': 'plain'},
+                   graph_attr={'pack': '1'})
+    g.graph_attr['rankdir'] = 'LR'
+
+    for n in lvl_nodes:
+        colors = NODE_COLORS[NODE_NAMESPACE_MAPPING.get(n.full_name.strip("/").split("/")[0])]
+        peripheries = "1" if n.full_name not in output_nodes else "2"
+        g.node(n.full_name, label=n.full_name, fillcolor=colors["fill"], color=colors["stroke"],
+               shape="box", style="filled", peripheries=peripheries)
+
+        if n.full_name in input_nodes:
+            helper_node_name = f"{n.full_name}__before"
+            g.node(helper_node_name, label="", shape="none", height="0", width="0")
+            g.edge(helper_node_name, n.full_name)
+
+    def compute_e2e_paths(start_nodes, end_nodes, edges):
+        frontier_paths = [[n] for n in start_nodes]
+        final_paths = []
+
+        while frontier_paths:
+            frontier_paths_new = []
+
+            for path in frontier_paths:
+                head = path[-1]
+                if head in end_nodes:
+                    final_paths.append(path)
+                    continue
+
+                out_nodes = [n_to for n_from, n_to in edges if n_from == head if n_to not in path]
+                new_paths = [path + [n] for n in out_nodes]
+                frontier_paths_new += new_paths
+
+            frontier_paths = frontier_paths_new
+
+        final_paths = [[(n_from, n_to)
+                        for n_from, n_to in zip(path[:-1], path[1:])]
+                       for path in final_paths]
+        return final_paths
+
+    e2e_paths = compute_e2e_paths(input_nodes, output_nodes, edges_between_nodes)
+
+    for (src_name, dst_name), edges in edges_between_nodes.items():
+        print(src_name, dst_name, len(edges))
+        color = "black" if any((src_name, dst_name) in path for path in e2e_paths) else "tomato"
+        g.edge(src_name, dst_name, penwidth=str(math.log(len(edges)) * 2 + .2), color=color)
+
+    g.save(f"{filename}.gv")
+    g.render(f"{filename}.svg")
+
+    return g

latency_graph/latency_graph_structure.py

@@ -1,18 +1,16 @@
 from bisect import bisect_left, bisect_right
 from collections import defaultdict
 from dataclasses import dataclass
-from itertools import combinations
-from multiprocessing import Pool
-from typing import Optional, Set, List, Iterable, Dict, Tuple
 from functools import cache
+from itertools import combinations
+from typing import Optional, Set, List, Iterable, Dict
+from uuid import UUID, uuid4
 
-import numpy as np
 from tqdm import tqdm
-from tqdm.contrib import concurrent
 
 from matching.subscriptions import sanitize
-from tracing_interop.tr_types import TrContext, TrCallbackObject, TrCallbackSymbol, TrNode, TrPublisher, TrSubscription, \
+from tracing_interop.tr_types import TrContext, TrCallbackObject, TrCallbackSymbol, TrNode, TrPublisher, TrTimer, \
-    TrTimer, TrPublishInstance, TrSubscriptionObject, TrTopic, TrCallbackInstance, Timestamp
+    TrSubscriptionObject, TrTopic
 
 TOPIC_FILTERS = ["/parameter_events", "/tf_static", "/robot_description", "diagnostics", "/rosout"]
 
@@ -203,6 +201,8 @@ class LatencyGraph:
     cb_pubs: Dict[TrCallbackObject, Set[TrPublisher]]
     pub_cbs: Dict[TrPublisher, Set[TrCallbackObject]]
 
+    _uuid: UUID
+
     def __init__(self, tr: TrContext):
         ##################################################
         # Annotate nodes with their callbacks
@@ -290,3 +290,10 @@ class LatencyGraph:
         ##################################################
 
         self.top_node = _hierarchize(lg_nodes)
+        self._uuid = uuid4()
+
+    def __hash__(self):
+        return hash(self._uuid)
+
+    def __eq__(self, other):
+        return isinstance(other, LatencyGraph) and other._uuid == self._uuid

latency_graph/message_tree.py

@@ -1,31 +0,0 @@
-from dataclasses import dataclass
-from typing import List
-
-from tracing_interop.tr_types import TrPublishInstance, TrCallbackInstance
-
-
-@dataclass
-class DepTree:
-    head: TrCallbackInstance | TrPublishInstance
-    deps: List['DepTree']
-
-    def depth(self):
-        return 1 + max(map(DepTree.depth, self.deps), default=0)
-
-    def size(self):
-        return 1 + sum(map(DepTree.size, self.deps))
-
-    def fanout(self):
-        if not self.deps:
-            return 1
-
-        return sum(map(DepTree.fanout, self.deps))
-
-    def e2e_lat(self):
-        return self.head.timestamp - self.critical_path()[-1].timestamp
-
-    def critical_path(self):
-        if not self.deps:
-            return [self.head]
-
-        return [self.head, *min(map(DepTree.critical_path, self.deps), key=lambda ls: ls[-1].timestamp)]

message_tree/message_tree_algorithms.py

@@ -0,0 +1,335 @@
+import re
+from bisect import bisect_right
+from collections import defaultdict
+from functools import cache
+from typing import List
+
+from tqdm import tqdm
+
+from latency_graph.latency_graph_structure import LatencyGraph
+from matching.subscriptions import sanitize
+from message_tree.message_tree_structure import DepTree, E2EBreakdownItem
+from tracing_interop.tr_types import TrCallbackInstance, TrPublishInstance, TrPublisher, TrCallbackObject, TrContext, \
+    TrSubscriptionObject, TrTimer, TrNode, TrTopic
+
+
+__dep_tree_cache = {}
+
+
+def _repr(inst: TrCallbackInstance | TrPublishInstance):
+    """
+    If a string representation is found for `inst`, it is returned, else an empty string is returned.
+    """
+    match inst:
+        case TrPublishInstance(publisher=pub):
+            return pub.topic_name if pub else ""
+        case TrCallbackInstance(callback_obj=cb_obj):
+            cb_obj: TrCallbackObject
+            return repr(sanitize(cb_obj.callback_symbol.symbol)) if cb_obj and cb_obj.callback_symbol else ""
+    raise TypeError(f"Argument has to be callback or publish instance, is {type(inst).__name__}")
+
+
+def get_dep_tree(inst: TrPublishInstance | TrCallbackInstance, lat_graph: LatencyGraph, tr: TrContext,
+                 excluded_path_patterns, time_limit_s):
+    """
+    Finds all (desired) dependencies of a publish/callback instance and returns a dependency tree.
+
+    The dependencies can be filtered via `time_limit_s`, which is the maximum difference in start time between `inst`
+    and any dependency in the tree.
+    Another filter is `excluded_path_patterns`, which cuts off paths where one instance's string representation matches
+    any of the given regex patterns.
+    """
+
+
+    start_time = inst.timestamp
+
+    def __get_dep_tree(inst, is_dep_cb, visited=None):
+
+        # If inst owner has been visited already, skip (loop prevention)
+        if visited is not None and owner(inst) in visited:
+            return None
+
+        # If we want to retrieve the tree, look in the cache first
+        cache_key = (inst, is_dep_cb)
+        if cache_key in __dep_tree_cache:
+            return __dep_tree_cache[cache_key]
+
+        if visited is None:
+            visited = tuple()
+
+        if any(re.search(p, _repr(inst)) for p in excluded_path_patterns):
+            return None
+
+        if inst.timestamp - start_time > time_limit_s:
+            return None
+
+        children_are_dep_cbs = False
+
+        match inst:
+            case TrPublishInstance(publisher=pub):
+                deps = [get_msg_dep_cb(inst, lat_graph)]
+            case TrCallbackInstance() as cb_inst:
+                cb_inst: TrCallbackInstance
+                deps = [inst_get_dep_msg(cb_inst, tr)]
+                if not is_dep_cb:
+                    deps += inst_get_dep_insts(cb_inst, tr)
+                    children_are_dep_cbs = True
+            case _:
+                print("[WARN] Expected inst to be of type TrPublishInstance or TrCallbackInstance, "
+                      f"got {type(inst).__name__}")
+                return None
+        # print("Rec level", lvl)
+        deps = list(filter(None, deps))
+        # Copy visited set for each child because we don't want separate paths to interfere with each other
+        deps = [__get_dep_tree(dep, children_are_dep_cbs, {*visited, owner(inst)}) for dep in deps]
+        deps = list(filter(None, deps))
+
+        # Create tree instance, cache and return it
+        ret_tree = DepTree(inst, deps)
+        __dep_tree_cache[cache_key] = ret_tree
+        return ret_tree
+
+    return __get_dep_tree(inst, False)
+
+
+def build_dep_trees(end_topics, lat_graph, tr, excluded_path_patterns, time_limit_s):
+    """
+    Builds the dependency trees for all messages published in any of `end_topics` and returns them as a list.
+    """
+    all_trees = []
+    for end_topic in end_topics:
+        end_topic: TrTopic
+        print(f"====={end_topic.name}")
+
+        pubs = end_topic.publishers
+        for pub in pubs:
+            msgs = list(pub.instances)
+            for msg in tqdm(msgs, desc="Processing output messages"):
+                msg: TrPublishInstance
+                tree = get_dep_tree(msg, lat_graph, tr, excluded_path_patterns, time_limit_s)
+                all_trees.append(tree)
+    return all_trees
+
+
+def inst_get_dep_msg(inst: TrCallbackInstance, tr: TrContext):
+    if inst.callback_object not in tr.callback_objects.by_callback_object:
+        # print("Callback not found (2)")
+        return None
+
+    if not isinstance(inst.callback_obj.owner, TrSubscriptionObject):
+        # print(f"Wrong type: {type(inst.callback_obj.owner)}")
+        return None
+
+    sub_obj: TrSubscriptionObject = inst.callback_obj.owner
+    if sub_obj and sub_obj.subscription and sub_obj.subscription.topic:
+        # print(f"Subscription has no topic")
+        pubs = sub_obj.subscription.topic.publishers
+    else:
+        pubs = []
+
+    def _pub_latest_msg_before(pub: TrPublisher, inst):
+        i_latest_msg = bisect_right(pub.instances, inst.timestamp, key=lambda x: x.timestamp) - 1
+        if i_latest_msg < 0 or i_latest_msg >= len(pub.instances):
+            return None
+        latest_msg = pub.instances[i_latest_msg]
+        if latest_msg.timestamp >= inst.timestamp:
+            return None
+
+        return latest_msg
+
+    msgs = [_pub_latest_msg_before(pub, inst) for pub in pubs]
+    msgs = list(filter(None, msgs))
+    msgs.sort(key=lambda i: i.timestamp, reverse=True)
+    if msgs:
+        msg = msgs[0]
+        return msg
+
+    # print(f"No messages found for topic {sub_obj.subscription.topic}")
+    return None
+
+
+def inst_get_dep_insts(inst: TrCallbackInstance, tr: TrContext):
+    if inst.callback_object not in tr.callback_objects.by_callback_object:
+        # print("Callback not found")
+        return []
+    dep_cbs = get_cb_dep_cbs(inst.callback_obj, tr)
+
+    def _cb_to_chronological_inst(cb: TrCallbackObject, inst):
+        i_inst_latest = bisect_right(cb.callback_instances, inst.timestamp, key=lambda x: x.timestamp)
+
+        for inst_before in cb.callback_instances[i_inst_latest::-1]:
+            if inst_before.t_end < inst.timestamp:
+                return inst_before
+
+        return None
+
+    insts = [_cb_to_chronological_inst(cb, inst) for cb in dep_cbs]
+    insts = list(filter(None, insts))
+    return insts
+
+
+def get_cb_dep_cbs(cb: TrCallbackObject, tr: TrContext):
+    match cb.owner:
+        case TrSubscriptionObject() as sub_obj:
+            sub_obj: TrSubscriptionObject
+            owner = sub_obj.subscription.node
+        case TrTimer() as tmr:
+            tmr: TrTimer
+            owner = tmr.node
+        case _:
+            raise RuntimeError(f"Encountered {cb.owner} as callback owner")
+
+    owner: TrNode
+    dep_sub_objs = {sub.subscription_object for sub in owner.subscriptions}
+    dep_cbs = {tr.callback_objects.by_id.get(sub_obj.id) for sub_obj in dep_sub_objs if sub_obj is not None}
+    dep_cbs |= {tr.callback_objects.by_id.get(tmr.id) for tmr in owner.timers}
+    dep_cbs.discard(cb)
+    dep_cbs.discard(None)
+
+    return dep_cbs
+
+
+def get_msg_dep_cb(msg: TrPublishInstance, lat_graph: LatencyGraph):
+    """
+    For a given message instance `msg`, find the publishing callback,
+    as well as the message instances that callback depends on (transitively within its TrNode).
+    """
+
+    # Find CB instance that published msg
+    # print(f"PUB {msg.publisher.node.path if msg.publisher.node is not None else '??'} ==> {msg.publisher.topic_name}")
+    pub_cbs = lat_graph.pub_cbs.get(msg.publisher)
+    if pub_cbs is None:
+        # print("Publisher unknown to lat graph. Skipping.")
+        return None
+
+    # print(f"Found {len(pub_cbs)} pub cbs")
+    cb_inst_candidates = []
+    for cb in pub_cbs:
+        # print(f"  > CB ({len(cb.callback_instances)} instances): {cb.callback_symbol.symbol if cb.callback_symbol else cb.id}")
+        i_inst_after = bisect_right(cb.callback_instances, msg.timestamp, key=lambda x: x.timestamp)
+
+        for inst in cb.callback_instances[:i_inst_after]:
+            if msg.timestamp > inst.t_end:
+                continue
+
+            assert inst.t_start <= msg.timestamp <= inst.t_end
+
+            cb_inst_candidates.append(inst)
+
+    if len(cb_inst_candidates) > 1:
+        # print("Found multiple possible callbacks")
+        return None
+    if not cb_inst_candidates:
+        # print("Found no possible callbacks")
+        return None
+
+    dep_inst = cb_inst_candidates[0]
+    return dep_inst
+
+
+def e2e_paths_sorted_desc(tree: DepTree, input_topic_patterns):
+    """
+    Return all paths through `tree` that start with a callback instance publishing on a topic matching any of
+    `input_topic_patterns`. The paths are sorted by length in a descending manner (element 0 is longest).
+    """
+
+    def _collect_all_paths(t: DepTree):
+        return [(*_collect_all_paths(d), t.head) for d in t.deps]
+
+    def _trim_path(path):
+        valid_input = False
+        i = -1
+        for i, inst in enumerate(path):
+            match inst:
+                case TrPublishInstance(publisher=pub):
+                    pub: TrPublisher
+                    if pub and any(re.search(p, pub.topic_name) for p in input_topic_patterns):
+                        valid_input = True
+                        break
+
+        if not valid_input:
+            return None
+
+        if i == 0 or not isinstance(path[i - 1], TrCallbackInstance):
+            print(f"[WARN] Message has no publishing callback in dep tree.")
+            return path[i:]  # Return path from first message that fits an input topic pattern
+
+        return path[i - 1:]  # Return path from its publishing callback if it exists
+
+    paths = _collect_all_paths(tree)
+    paths = list(filter(lambda p: p is not None, map(_trim_path, tqdm(paths, desc="_trim_path"))))
+    paths.sort(key=lambda path: path[-1].timestamp - path[0].timestamp, reverse=True)
+    return paths
+
+
+def e2e_latency_breakdown(path: list):
+    """
+    Separates E2E latency into a sequence of dds, idle, and cpu times.
+    This method expects a publish instance at the last position in `path`.
+
+    The return format is a list of the form [("<type>", <time>), ("<type>", <time>), ...] with type bein gone of the
+    three mentioned above.
+    """
+    ret_list: List[E2EBreakdownItem] = []
+
+    cb_inst: TrCallbackInstance
+    cb_inst_prev: TrCallbackInstance
+    pub_inst: TrPublishInstance
+    pub_inst_prev: TrPublishInstance
+
+    last_inst = None
+    for inst in path:
+        match inst:
+            case TrCallbackInstance() as cb_inst:
+                match last_inst:
+                    case TrCallbackInstance() as cb_inst_prev:
+                        ret_list.append(E2EBreakdownItem("idle", cb_inst.t_start - cb_inst_prev.t_end,
+                                                         (cb_inst_prev, cb_inst)))
+                    case TrPublishInstance() as pub_inst_prev:
+                        ret_list.append(E2EBreakdownItem("dds", cb_inst.t_start - pub_inst_prev.timestamp,
+                                                         (pub_inst_prev, inst)))
+            case TrPublishInstance() as pub_inst:
+                match last_inst:
+                    case TrCallbackInstance() as cb_inst_prev:
+                        ret_list.append(E2EBreakdownItem("cpu", pub_inst.timestamp - cb_inst_prev.t_start,
+                                                         (cb_inst_prev, pub_inst)))
+                    case TrPublishInstance():
+                        raise TypeError(f"Found two publish instances in a row in an E2E path.")
+        last_inst = inst
+
+    if not isinstance(last_inst, TrPublishInstance):
+        raise TypeError(f"Last instance in path is not a message but a {type(last_inst).__name__}")
+
+    return ret_list
+
+
+@cache
+def owner(inst: TrCallbackInstance | TrPublishInstance):
+    match inst:
+        case TrCallbackInstance(callback_obj=cb_obj):
+            cb_obj: TrCallbackObject
+            if cb_obj and cb_obj.callback_symbol:
+                sym = repr(sanitize(cb_obj.callback_symbol.symbol))
+            else:
+                sym = str(cb_obj.id)
+            return sym
+        case TrPublishInstance(publisher=pub):
+            pub: TrPublisher
+            topic = pub.topic_name
+            return topic
+        case _:
+            raise ValueError()
+
+
+def _repr_path(path: List[TrPublishInstance | TrCallbackInstance]):
+    return " -> ".join(map(owner, path))
+
+
+def aggregate_e2e_paths(paths: List[List[TrPublishInstance | TrCallbackInstance]]):
+    path_cohorts = defaultdict(list)
+
+    for path in paths:
+        key = _repr_path(path)
+        path_cohorts[key].append(path)
+
+    return path_cohorts

message_tree/message_tree_plots.py

@@ -0,0 +1,49 @@
+from typing import List
+
+import matplotlib.pyplot as plt
+import numpy as np
+from matplotlib.axes import Axes
+from matplotlib.figure import Figure
+
+from message_tree.message_tree_structure import E2EBreakdownItem
+
+
+def e2e_breakdown_type_hist(items: List[E2EBreakdownItem]):
+    """
+    Given a list of e2e breakdown instances of the form `("<type>", <duration>)`, plots a histogram for each encountered
+    type.
+    """
+    plot_types = ("dds", "idle", "cpu")
+    assert all(item.type in plot_types for item in items)
+
+    fig: Figure
+    fig, axes = plt.subplots(1, 3, num="E2E type breakdown histograms")
+    fig.suptitle("E2E Latency Breakdown by Resource Type")
+
+    for type, ax in zip(plot_types, axes):
+        ax: Axes
+
+        durations = [item.duration for item in items if item.type == type]
+
+        ax.set_title(type)
+        ax.hist(durations)
+        ax.set_xlabel("Duration [s]")
+        ax.set_ylabel("Occurrences")
+
+    return fig
+
+
+def e2e_breakdown_inst_stack(*paths: List[E2EBreakdownItem]):
+    fig: Figure
+    ax: Axes
+    fig, ax = plt.subplots(num="E2E instance breakdown stackplot")
+    fig.suptitle("Detailed E2E Latency Path Breakdown")
+
+    bottom = 0
+    for i in range(len(paths)):
+        e2e_items = [path[i] for path in paths]
+        durations = np.array([item.duration for item in e2e_items])
+        ax.bar(range(len(paths)), durations, bottom=bottom)
+        bottom = durations + bottom
+
+    return fig

message_tree/message_tree_structure.py

@@ -0,0 +1,20 @@
+from collections import namedtuple
+
+
+E2EBreakdownItem = namedtuple("E2EBreakdownItem", ("type", "duration", "location"))
+DepTree = namedtuple("DepTree", ("head", "deps"))
+
+
+def depth(tree: DepTree):
+    return 1 + max(map(depth, tree.deps), default=0)
+
+
+def size(tree: DepTree):
+    return 1 + sum(map(size, tree.deps))
+
+
+def fanout(tree: DepTree):
+    if not tree.deps:
+        return 1
+
+    return sum(map(fanout, tree.deps))

tracing_interop/tr_types.py

@@ -1,3 +1,4 @@
+from uuid import UUID, uuid4
 from collections import namedtuple, UserList, defaultdict
 from dataclasses import dataclass, field
 from functools import cached_property
@@ -75,6 +76,7 @@ class TrContext:
     publish_instances: Index['TrPublishInstance']
     callback_instances: Index['TrCallbackInstance']
     topics: Index['TrTopic']
+    _uuid: UUID
 
     def __init__(self, handler: Ros2Handler):
         print("[TrContext] Processing ROS 2 objects from traces...")
@@ -110,6 +112,14 @@ class TrContext:
         self.topics = Index((TrTopic(name=name, _c=self) for name in _unique_topic_names),
                             name=False)
 
+        self._uuid = uuid4()
+
+    def __hash__(self):
+        return hash(self._uuid)
+
+    def __eq__(self, other):
+        return isinstance(other, TrContext) and other._uuid == self._uuid
+
     def __repr__(self):
         return f"TrContext"