User:Tekkub/Table profiling

From WoWWiki

local p = function(t)
ChatFrame1:AddMessage(t)
end

collectgarbage("stop")

for pow=6,9 do
local limit = math.pow(2,pow)
p("------ "..limit.." ------")

collectgarbage("collect")

local mem, time
local numt = 1000
local tables = {}
local gcalloc = {}
local v = "Blah"
for i=1,limit do 
  gcalloc [i] = v
  gcalloc [tostring(i)] = v 
end

-------------

for i=1,numt do 
  tables[i] = {}
  for j=1,limit do tables[i][j] = v end
end

tables = {}

time, mem = GetTime(), collectgarbage("count")
collectgarbage("collect")
p(string.format("GC array: %.03f sec  %d B", GetTime()-time, (collectgarbage("count")-mem)*1024))

------------------

for i=1,numt do 
  tables[i] = {}
  for j=1,limit do tables[i][j] = v end
end

time, mem = GetTime(), collectgarbage("count")
for i=1,numt do 
  for j in pairs(tables[i]) do tables[i][j] = nil end
end
p(string.format("Erase array: %.03f sec  %d B", GetTime()-time, (collectgarbage("count")-mem)*1024))

------------------

for i=1,numt do 
  tables[i] = {}
  for j=1,limit do tables[i][j] = v end
end

time, mem = GetTime(), collectgarbage("count")
for i=1,numt do 
  for j in pairs(tables[i]) do tables[i][j] = nil end
  tables[i].blah = v
  tables[i].blah = nil
end
p(string.format("Erase/shrink array: %.03f sec  %d B", GetTime()-time, (collectgarbage("count")-mem)*1024))

------------

for i=1,numt do 
  tables[i] = {}
  for j=1,limit do tables[i][tostring(j)] = v end
end
collectgarbage("collect")
tables = {}

time, mem = GetTime(), collectgarbage("count")
collectgarbage("collect")
p(string.format("GC Hash: %.03f sec  %d B", GetTime()-time, (collectgarbage("count")-mem)*1024))

------------------

tables = {}
for i=1,numt do 
  tables[i] = {}
  for j=1,limit do tables[i][tostring(j)] = v end
end

time, mem = GetTime(), collectgarbage("count")
for i=1,numt do 
  for j in pairs(tables[i]) do tables[i][j] = nil end
  tables[i].blah = v
  tables[i].blah = nil
end
p(string.format("Erase Hash: %.03f sec  %d B", GetTime()-time, (collectgarbage("count")-mem)*1024))

end

Results:

------ 64 ------
GC array: 0.054 sec  -1076763 B
Erase array: 0.032 sec  0 B
Erase/shrink array: 0.037 sec  -984000 B
GC Hash: 0.056 sec  -2612420 B
Erase Hash: 0.033 sec  0 B
------ 128 ------
GC array: 0.052 sec  -2100420 B
Erase array: 0.064 sec  0 B
Erase/shrink array: 0.067 sec  -2008000 B
GC Hash: 0.058 sec  -5172420 B
Erase Hash: 0.066 sec  0 B
------ 256 ------
GC array: 0.058 sec  -4148420 B
Erase array: 0.133 sec  0 B
Erase/shrink array: 0.137 sec  -4056000 B
GC Hash: 0.063 sec  -10292420 B
Erase Hash: 0.134 sec  0 B
------ 512 ------
GC array: 0.060 sec  -8244420 B
Erase array: 0.286 sec  -52 B
Erase/shrink array: 0.268 sec  -8152000 B
GC Hash: 0.069 sec  -20532420 B
Erase Hash: 0.266 sec  0 B