commit | 5bba342933eac5f71ad91b35bd601dbc6d795acd | [log] [tgz] |
---|---|---|
author | Evan Jones <ej@evanjones.ca> | Sun Mar 13 22:18:25 2022 -0400 |
committer | GitHub <noreply@github.com> | Sun Mar 13 19:18:25 2022 -0700 |
tree | 3b5aa2ea5472f6ce104106a747f25b135aa650aa | |
parent | 0368bd9e19a701277ef7ee067e44c2ac85f349b1 [diff] |
internal/graph: Support comments with double quotes (#688) The first comment in a pprof file is used as the subgraph ID for the legend, but was not escaped. If the comment contained double quotes, it could cause graphviz to fail to parse the output, or to render incorrect graphs. To reproduce, run the following commands: $ pprof -add_comment "unterminated \"double quote" -proto -output=bug.pprof in.pprof Generating report in labels-no-specials-unterminated-double-quote.pprof $ pprof -comments bug.pprof unterminated "double quote $ pprof -web bug.pprof Error: <stdin>: syntax error in line 3 near '\' pprof: failed to execute dot. Is Graphviz installed? Error: exit status 1 Add a test for this case. Without the change to dotgraph.go, the test produced the following dot output: digraph "testtitle" { node [style=filled fillcolor="#f8f8f8"] subgraph cluster_L { "comment line 1 comment line 2 "unterminated double quote" [shape=box fontsize=16 label="comment line 1\lcomment line 2 \"unterminated double quote\lsecond comment \"double quote\"\l" tooltip="testtitle"] } N1 [label="src\n10 (10.00%)\nof 25 (25.00%)" id="node1" fontsize=22 shape=box tooltip="src (25)" color="#b23c00" fillcolor="#edddd5"] N2 [label="dest\n15 (15.00%)\nof 25 (25.00%)" id="node2" fontsize=24 shape=box tooltip="dest (25)" color="#b23c00" fillcolor="#edddd5"] N1 -> N2 [label=" 10" weight=11 color="#b28559" tooltip="src -> dest (10)" labeltooltip="src -> dest (10)"] } This failed to parse with dot: $ dot ./internal/graph/testdata/compose9.dot Error: ./internal/graph/testdata/compose9.dot: syntax error in line 4 near '\' After adding the escaping, the test case now parses with dot, and the new test case works as expected.
pprof is a tool for visualization and analysis of profiling data.
pprof reads a collection of profiling samples in profile.proto format and generates reports to visualize and help analyze the data. It can generate both text and graphical reports (through the use of the dot visualization package).
profile.proto is a protocol buffer that describes a set of callstacks and symbolization information. A common usage is to represent a set of sampled callstacks from statistical profiling. The format is described on the proto/profile.proto file. For details on protocol buffers, see https://developers.google.com/protocol-buffers
Profiles can be read from a local file, or over http. Multiple profiles of the same type can be aggregated or compared.
If the profile samples contain machine addresses, pprof can symbolize them through the use of the native binutils tools (addr2line and nm).
This is not an official Google product.
Prerequisites:
Go development kit of a supported version. Follow these instructions to prepare the environment.
Graphviz: http://www.graphviz.org/ Optional, used to generate graphic visualizations of profiles
To build and install it:
go install github.com/google/pprof@latest
The binary will be installed $GOPATH/bin
($HOME/go/bin
by default).
pprof can read a profile from a file or directly from a server via http. Specify the profile input(s) in the command line, and use options to indicate how to format the report.
% pprof -top [main_binary] profile.pb.gz Where main_binary: Local path to the main program binary, to enable symbolization profile.pb.gz: Local path to the profile in a compressed protobuf, or URL to the http service that serves a profile.
pprof -web [main_binary] profile.pb.gz
If no output formatting option is specified, pprof runs on interactive mode, where reads the profile and accepts interactive commands for visualization and refinement of the profile.
pprof [main_binary] profile.pb.gz This will open a simple shell that takes pprof commands to generate reports. Type 'help' for available commands/options.
If the -http
flag is specified, pprof starts a web server at the specified host:port that provides an interactive web-based interface to pprof. Host is optional, and is “localhost” by default. Port is optional, and is a random available port by default. -http=":"
starts a server locally at a random port.
pprof -http=[host]:[port] [main_binary] profile.pb.gz
The preceding command should automatically open your web browser at the right page; if not, you can manually visit the specified port in your web browser.
pprof can read perf.data
files generated by the Linux perf tool by using the perf_to_profile
program from the perf_data_converter package.
To view disassembly of profiles collected from Go programs compiled as Windows executables, the executable must be built with go build -buildmode=exe
. LLVM or GCC must be installed, so required tools like addr2line
and nm
are available to pprof
.
See doc/README.md for more detailed end-user documentation.
See CONTRIBUTING.md for contribution documentation.
See proto/README.md for a description of the profile.proto format.