benchmarks: Split out suites

Split suites out into individual files
Provide usage info when run without BENCHMARK env var
Add option to save logs to output file
Add DTable CSV/Arrow reading suite

Author: jpsamaroo

Diff for: benchmarks/analysis.jl

@@ -0,0 +1,43 @@
+path = ARGS[1]
+start, finish = parse.(UInt64, ARGS[2:3])
+
+using DataFrames, BenchmarkTools, Dagger, Serialization
+
+logs = deserialize(path)["logs"]
+
+"""
+    spans(logs::DataFrame) -> DataFrame
+
+Combines start and finish event pairs, and computes their timespan.
+"""
+function spans(logs)
+    df = Any[]
+    evs = Dict{Symbol,Dict{Any,Any}}()
+    for log in eachrow(logs)
+        _evs = get!(evs, log.core.category) do
+            Dict{Any,Any}()
+        end
+        if log.core.kind == :finish
+            if haskey(_evs, log.id)
+                start = pop!(_evs, log.id)
+                ev = merge(log, (;span=(start.core.timestamp, log.core.timestamp)))
+                push!(df, ev)
+            else
+                @warn "Dropped :finish for $(log.core.category)"
+            end
+        elseif log.core.kind == :start
+            _evs[log.id] = log
+        end
+    end
+    DataFrame(df)
+end
+
+# Combine, select target range, and filter out `take`
+tgt = subset(spans(logs), :core=>ByRow(x->start <= x.timestamp <= finish),
+                          :core=>ByRow(x->x.category != :take))
+
+# Sort by largest time contribution
+tgt_sort = DataFrame(sort(eachrow(tgt), by=r->r.span[2] - r.span[1], rev=true))
+transform!(tgt_sort, :span=>ByRow(s->(s[2]-s[1]) / (1000^3))=>:span_s)
+println("Total: $((finish-start) / (1000^3))")
+foreach(println, zip(map(c->c.category, tgt_sort.core), tgt_sort.span_s))