ninjaString is an interface, which uses 16 bytes of memory on top
of the size of the concrete type. A literalNinjaString is a string,
which is another 16 bytes for the string header for a total of 32
bytes. A varNinjaString is two slices, which are 24 bytes each
for the slice headers, for a total of 64 bytes. The slices contain
the first constant string, and then altenrating variable and string
parts of the ninjaString, resulting in 16 bytes plus 32 bytes per
variable.
This patch replaces the ninjaString interface with a *ninjaString
concrete struct type. The ninjaString struct is a string and a
pointer to a slice of variable references, for a total of 24 bytes.
ninjaStrings with no variable references (the equivalent of the old
literalNinjaString) have a nil slice, and now use 24 bytes instead
of 32 bytes.
ninjaStrings with variable references allocate a slice of variable
references that contain 32-bit start and end offsets and a Variable
interface, but reuse the original string and so avoid the extra
string headers, resulting in 24 bytes for the slice header, and
24 bytes per variable.
These savings reduce the peak memory usage averaged across 10 runs of
/bin/time -v build/soong/soong_ui.bash --make-mode nothing
on the internal master branch cf_x86_64_phone-userdebug build
from 50114842kB to 45577638kB, a savings of 4537204kB or 9%.
The new Benchmark_parseNinjaString shows savings in both time and
memory. Before:
Benchmark_parseNinjaString/constant/1-128 594251787 2.006 ns/op 0 B/op 0 allocs/op
Benchmark_parseNinjaString/constant/10-128 21191347 65.57 ns/op 16 B/op 1 allocs/op
Benchmark_parseNinjaString/constant/100-128 9983748 130.2 ns/op 112 B/op 1 allocs/op
Benchmark_parseNinjaString/constant/1000-128 2632527 445.1 ns/op 1024 B/op 1 allocs/op
Benchmark_parseNinjaString/variable/1-128 2964896 419.4 ns/op 176 B/op 4 allocs/op
Benchmark_parseNinjaString/variable/10-128 1807341 670.6 ns/op 192 B/op 7 allocs/op
Benchmark_parseNinjaString/variable/100-128 1000000 1092 ns/op 352 B/op 7 allocs/op
Benchmark_parseNinjaString/variable/1000-128 300649 3773 ns/op 1584 B/op 7 allocs/op
Benchmark_parseNinjaString/variables/1-128 2858432 441.6 ns/op 176 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/2-128 2360505 513.4 ns/op 208 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/3-128 1867136 635.6 ns/op 240 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/4-128 1584045 752.1 ns/op 272 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/5-128 1338189 885.8 ns/op 304 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/10-128 1000000 1468 ns/op 464 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/100-128 88768 12895 ns/op 3712 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/1000-128 8972 133627 ns/op 32896 B/op 4 allocs/op
After:
Benchmark_parseNinjaString/constant/1-128 584600864 2.004 ns/op 0 B/op 0 allocs/op
Benchmark_parseNinjaString/constant/10-128 19274581 64.84 ns/op 16 B/op 1 allocs/op
Benchmark_parseNinjaString/constant/100-128 9017640 127.6 ns/op 112 B/op 1 allocs/op
Benchmark_parseNinjaString/constant/1000-128 2630797 453.0 ns/op 1024 B/op 1 allocs/op
Benchmark_parseNinjaString/variable/1-128 3460422 347.0 ns/op 136 B/op 4 allocs/op
Benchmark_parseNinjaString/variable/10-128 2103404 519.9 ns/op 152 B/op 7 allocs/op
Benchmark_parseNinjaString/variable/100-128 1315778 906.5 ns/op 312 B/op 7 allocs/op
Benchmark_parseNinjaString/variable/1000-128 354812 3284 ns/op 1544 B/op 7 allocs/op
Benchmark_parseNinjaString/variables/1-128 3386868 361.5 ns/op 136 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/2-128 2675594 456.9 ns/op 160 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/3-128 2344670 520.0 ns/op 192 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/4-128 1919482 648.1 ns/op 208 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/5-128 1560556 723.9 ns/op 240 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/10-128 1000000 1169 ns/op 352 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/100-128 116738 10168 ns/op 2800 B/op 4 allocs/op
Benchmark_parseNinjaString/variables/1000-128 10000 105646 ns/op 24688 B/op 4 allocs/op
Bug: 286423944
Test: ninja_strings_test.go
Test: out/soong/build*.ninja is the same before and after this change
Change-Id: I1ecffbaccb0d0469a41fa31255c1b17311e01687
Add a VariableFuncContext argument to VariableFuncs that implements
GlobWithDeps. This will allow Soong to use optimized glob dependencies
in VariableFuncs.
Bug: 257079828
Test: no dependencies on directories in build.ninja.d
Change-Id: Iee5fc9c9ae3087662a5d1a3d7323a87462299205
Variables, pools and rules each computed their full names every time
they were referenced, which required string concatenations. Since
every one is guaranteed to be accessed at least twice, once when the
definition is written into the ninja file and once for each reference,
precompute the full name. For local variables that can be done
during initialization, but for global variables add a pass to
PrepareBuildActions to compute the name for each live variable using
the final package names.
Test: ninja_writer_test.go
Change-Id: I2264b05e0409e36651db2fb5d463c16c698d4d5e
There are 8935901 *ninjaString objects generated in an AOSP
aosp_blueline-userdebug build, and 7865180 of those are a literal
string with no ninja variables.
Each of those *ninjaString objects takes a minimum of 48 bytes for
2 slices, plus 8 bytes for the pointer to the ninjaString. For
the literal string case, one of those slices has a single element,
(costing another 16 bytes for the backing array), and the other
slice is empty, for a total of 72 bytes.
Replace *ninjaString with a ninjaString interface. This increases
the size of the reference from 8 bytes to 16 bytes, but using
a type alias of a string for the literal string implementation uses
only 16 bytes, saving 40 bytes per literal string or 314 MB.
Test: ninja_strings_test
Change-Id: Ic5fe16ed1f2a244fe6a8ccdf762919634d825cbe
Turn PackageContext into an interface so that build systems can wrap it
to add more custom helpers.
This does introduce an API change, though it should be fairly simple.
NewPackageContext used to provide an opaque *PackageContext struct, now it
provides a PackageContext interface.
Change-Id: I383c64a303d857ef5e0dec86ad77f791ba4c9639
Make integrating with go tools easier by putting the blueprint package
files in the top level directory of the git project instead of in a
subdirectory called blueprint.
Change-Id: I35c144c5fe7ddf34e478d0c47c50b2f6c92c2a03
