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lib/dala_dev/crash_dump.ex
defmodule DalaDev.CrashDump do
@moduledoc """
Parse BEAM crash dumps from devices.
BEAM crash dumps are text files generated when an Erlang VM crashes.
This module parses them to extract useful information for debugging
dala Elixir nodes.
## Examples
# Parse a crash dump file
{:ok, info} = DalaDev.CrashDump.parse_file("erl_crash.dump")
# Parse from a device
{:ok, info} = DalaDev.CrashDump.fetch_from_device(node, "/path/to/crash.dump")
# Generate a summary report
report = DalaDev.CrashDump.summary(info)
"""
@type crash_info :: %{
header: map(),
system_info: map(),
process_info: [map()],
ports: [map()],
ets_tables: [map()],
timers: [map()],
error_info: map() | nil,
memory: map(),
summary: String.t()
}
@doc """
Parse a crash dump file.
Returns a crash_info map with all parsed sections.
"""
@spec parse_file(String.t()) :: {:ok, crash_info()} | {:error, term()}
def parse_file(path) when is_binary(path) do
case File.read(path) do
{:ok, content} -> parse(content)
error -> error
end
end
@doc """
Parse crash dump content from a string.
Returns a crash_info map with all parsed sections.
"""
@spec parse(String.t()) :: {:ok, crash_info()} | {:error, term()}
def parse(content) when is_binary(content) do
try do
lines = String.split(content, "\n")
header = parse_header(lines)
system_info = parse_system_info(lines)
process_info = parse_processes(lines)
ports = parse_ports(lines)
ets_tables = parse_ets_tables(lines)
timers = parse_timers(lines)
error_info = parse_error_info(lines)
memory = parse_memory(lines)
info = %{
header: header,
system_info: system_info,
process_info: process_info,
ports: ports,
ets_tables: ets_tables,
timers: timers,
error_info: error_info,
memory: memory,
summary: generate_summary(header, error_info, memory)
}
{:ok, info}
rescue
e -> {:error, Exception.message(e)}
end
end
@doc """
Fetch a crash dump from a remote device and parse it.
Options:
- `:timeout` - RPC timeout in ms (default: 30_000)
"""
@spec fetch_from_device(node(), String.t(), keyword()) :: {:ok, crash_info()} | {:error, term()}
def fetch_from_device(node, remote_path, opts \\ []) do
timeout = Keyword.get(opts, :timeout, 30_000)
case :rpc.call(node, File, :read, [remote_path], timeout) do
{:badrpc, reason} -> {:error, {:rpc_error, reason}}
{:ok, content} -> parse(content)
{:error, _} = error -> error
content when is_binary(content) -> parse(content)
end
end
@doc """
Generate a human-readable summary of the crash dump.
"""
@spec summary(crash_info()) :: String.t()
def summary(info) do
"""
BEAM Crash Dump Summary
=======================
#{summary_header(info.header)}
#{summary_error(info.error_info)}
#{summary_memory(info.memory)}
#{summary_processes(info.process_info)}
System Info:
OTP Release: #{get_in(info.system_info, [:otp_release]) || "unknown"}
Elixir Version: #{get_in(info.system_info, [:elixir_version]) || "unknown"}
Node: #{get_in(info.system_info, [:node]) || "unknown"}
Top Processes by Memory:
#{top_processes_by_memory(info.process_info, 5)}
ETS Tables: #{length(info.ets_tables)}
Timers: #{length(info.timers)}
"""
end
@doc """
Generate an HTML report from crash dump info.
"""
@spec html_report(crash_info()) :: String.t()
def html_report(info) do
"""
<!DOCTYPE html>
<html>
<head>
<title>BEAM Crash Dump Report</title>
<script src="https://cdn.tailwindcss.com"></script>
</head>
<body class="bg-zinc-950 text-zinc-200 p-8">
<h1 class="text-2xl font-bold mb-6">BEAM Crash Dump Report</h1>
<div class="mb-8">
<h2 class="text-xl font-semibold mb-4">Error Information</h2>
#{error_html(info.error_info)}
</div>
<div class="mb-8">
<h2 class="text-xl font-semibold mb-4">Memory</h2>
#{memory_html(info.memory)}
</div>
<div class="mb-8">
<h2 class="text-xl font-semibold mb-4">Top Processes</h2>
#{processes_html(info.process_info)}
</div>
<div class="mb-8">
<h2 class="text-xl font-semibold mb-4">System Info</h2>
#{system_info_html(info.system_info)}
</div>
</body>
</html>
"""
end
# ── Parsing helpers ──────────────────────────────
defp parse_header(lines) do
%{}
|> maybe_put(:crash_dump_version, find_line_value(lines, "Crash dump created on"))
|> maybe_put(:created_at, find_line_value(lines, "Crash dump created on"))
end
defp parse_system_info(lines) do
%{}
|> maybe_put(:otp_release, find_line_value(lines, "OTP release"))
|> maybe_put(:elixir_version, find_line_value(lines, "Elixir version"))
|> maybe_put(:node, find_line_value(lines, "Node name"))
|> maybe_put(:compile_time, find_line_value(lines, "Compile time"))
end
defp parse_processes(_lines) do
# Simplified - would parse actual process entries
[]
end
defp parse_ports(_lines) do
[]
end
defp parse_ets_tables(_lines) do
[]
end
defp parse_timers(_lines) do
[]
end
defp parse_error_info(lines) do
error_type = find_line_value(lines, "Error in process")
error_reason = find_line_value(lines, "Error reason")
if error_type || error_reason do
%{
type: error_type,
reason: error_reason
}
else
nil
end
end
defp parse_memory(lines) do
%{
total: find_line_value(lines, "Memory total"),
processes: find_line_value(lines, "Memory processes"),
system: find_line_value(lines, "Memory system")
}
end
defp find_line_value(lines, pattern) do
Enum.find_value(lines, fn line ->
if String.contains?(line, pattern) do
line
|> String.split(":", parts: 2)
|> case do
[_, value] -> String.trim(value)
_ -> nil
end
end
end)
end
defp maybe_put(map, _key, nil), do: map
defp maybe_put(map, key, value), do: Map.put(map, key, value)
# ── Summary helpers ──────────────────────────────
defp generate_summary(header, _error_info, _memory) do
"Crash dump parsed: #{Map.get(header, :created_at, "unknown time")}"
end
defp summary_header(header) do
"Created at: #{Map.get(header, :created_at, "unknown")}\n"
end
defp summary_error(nil), do: "No error information found.\n"
defp summary_error(error) do
"""
Error: #{Map.get(error, :type, "unknown")}
Reason: #{Map.get(error, :reason, "unknown")}
"""
end
defp summary_memory(memory) do
"""
Memory:
Total: #{Map.get(memory, :total, "unknown")}
Processes: #{Map.get(memory, :processes, "unknown")}
System: #{Map.get(memory, :system, "unknown")}
"""
end
defp summary_processes(processes) do
"Processes found: #{length(processes)}\n"
end
defp top_processes_by_memory(processes, count) do
if processes == [] do
" (parsing not fully implemented yet)\n"
else
processes
|> Enum.sort_by(& &1.memory, &>=/2)
|> Enum.take(count)
|> Enum.with_index()
|> Enum.map(fn {proc, i} ->
" #{i + 1}. #{proc.name || proc.pid} - #{proc.memory} bytes\n"
end)
|> Enum.join()
end
end
# ── HTML helpers ──────────────────────────────
defp error_html(nil), do: "<p>No error information</p>"
defp error_html(error) do
"""
<div class="bg-red-900/20 p-4 rounded">
<p><strong>Type:</strong> #{Map.get(error, :type, "unknown")}</p>
<p><strong>Reason:</strong> #{Map.get(error, :reason, "unknown")}</p>
</div>
"""
end
defp memory_html(memory) do
"""
<div class="grid grid-cols-3 gap-4">
<div class="bg-zinc-800 p-4 rounded">
<div class="text-sm text-zinc-400">Total</div>
<div class="text-xl">#{Map.get(memory, :total, "N/A")}</div>
</div>
<div class="bg-zinc-800 p-4 rounded">
<div class="text-sm text-zinc-400">Processes</div>
<div class="text-xl">#{Map.get(memory, :processes, "N/A")}</div>
</div>
<div class="bg-zinc-800 p-4 rounded">
<div class="text-sm text-zinc-400">System</div>
<div class="text-xl">#{Map.get(memory, :system, "N/A")}</div>
</div>
</div>
"""
end
defp processes_html(processes) do
if processes == [] do
"<p>Process parsing not yet implemented.</p>"
else
# Would generate table
"<p>Found #{length(processes)} processes</p>"
end
end
defp system_info_html(info) do
"""
<dl class="grid grid-cols-2 gap-2">
<dt class="text-zinc-400">OTP Release</dt>
<dd>#{Map.get(info, :otp_release, "N/A")}</dd>
<dt class="text-zinc-400">Elixir Version</dt>
<dd>#{Map.get(info, :elixir_version, "N/A")}</dd>
<dt class="text-zinc-400">Node</dt>
<dd>#{Map.get(info, :node, "N/A")}</dd>
</dl>
"""
end
end