Remove some unsafe and allocations when creating PrimitiveArrays from Vec and from_trusted_len_iter

[alamb]

Which issue does this PR close?

• part of [Epic] Replace ArrayData with direct Array construction, when possible #9298

Rationale for this change

While reviewing #9294 from @Dandandan I noticed some other places where we can avoid making ArrayData and thus save some allocations (and unsafe)

I don't expect this to make a huge performance difference, but every little allocation helps, and I think the change is justified simply from the perspective of avoiding some more unsafe

What changes are included in this PR?

Construct primitive arrays directly

Are these changes tested?

By existing CI

Are there any user-facing changes?

[alamb]

Note the

1. no more unsafe
2. Use avoid vec![buffer] allocation

[alamb]

run benchmark arrow_statistics

[alamb-ghbot]

🤖 ./gh_compare_arrow.sh gh_compare_arrow.sh Running
Linux aal-dev 6.14.0-1018-gcp #19~24.04.1-Ubuntu SMP Wed Sep 24 23:23:09 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
Comparing alamb/faster_safer (027d9e2) to 6c54276 diff
BENCH_NAME=arrow_statistics
BENCH_COMMAND=cargo bench --features=arrow,async,test_common,experimental,object_store --bench arrow_statistics
BENCH_FILTER=
BENCH_BRANCH_NAME=alamb_faster_safer
Results will be posted here when complete

[alamb-ghbot]

🤖: Benchmark completed

Details

group                                                                                                      alamb_faster_safer                     main
-----                                                                                                      ------------------                     ----
Extract data page statistics for Dictionary(Int32, String)/extract_statistics/Dictionary(Int32, String)    1.00     70.2±1.03µs        ? ?/sec    1.01     70.8±0.85µs        ? ?/sec
Extract data page statistics for F64/extract_statistics/F64                                                1.00     11.6±0.42µs        ? ?/sec    1.00     11.6±0.22µs        ? ?/sec
Extract data page statistics for Int64/extract_statistics/Int64                                            1.02     13.5±0.15µs        ? ?/sec    1.00     13.2±0.44µs        ? ?/sec
Extract data page statistics for String/extract_statistics/String                                          1.00     69.7±0.36µs        ? ?/sec    1.01     70.3±0.48µs        ? ?/sec
Extract data page statistics for UInt64/extract_statistics/UInt64                                          1.01     11.7±0.11µs        ? ?/sec    1.00     11.6±0.08µs        ? ?/sec
Extract row group statistics for Dictionary(Int32, String)/extract_statistics/Dictionary(Int32, String)    1.00  1026.6±35.01ns        ? ?/sec    1.01  1037.8±30.66ns        ? ?/sec
Extract row group statistics for F64/extract_statistics/F64                                                1.01   541.9±12.66ns        ? ?/sec    1.00    535.8±9.72ns        ? ?/sec
Extract row group statistics for Int64/extract_statistics/Int64                                            1.00    544.0±7.37ns        ? ?/sec    1.00   544.9±24.83ns        ? ?/sec
Extract row group statistics for String/extract_statistics/String                                          1.00  1029.0±11.00ns        ? ?/sec    1.00  1030.4±10.23ns        ? ?/sec
Extract row group statistics for UInt64/extract_statistics/UInt64                                          1.01    542.9±9.59ns        ? ?/sec    1.00   538.2±21.77ns        ? ?/sec

[alamb]

run benchmark builder

[alamb-ghbot]

🤖 ./gh_compare_arrow.sh gh_compare_arrow.sh Running
Linux aal-dev 6.14.0-1018-gcp #19~24.04.1-Ubuntu SMP Wed Sep 24 23:23:09 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
Comparing alamb/faster_safer (027d9e2) to 6c54276 diff
BENCH_NAME=builder
BENCH_COMMAND=cargo bench --features=arrow,async,test_common,experimental,object_store --bench builder
BENCH_FILTER=
BENCH_BRANCH_NAME=alamb_faster_safer
Results will be posted here when complete

[alamb-ghbot]

🤖: Benchmark completed

Details

group                                          alamb_faster_safer                     main
-----                                          ------------------                     ----
bench_bool/bench_bool                          1.00  1033.7±15.97µs   483.7 MB/sec    1.00  1034.9±27.70µs   483.1 MB/sec
bench_decimal128_builder                       1.00     80.9±0.27µs        ? ?/sec    1.03     83.5±1.37µs        ? ?/sec
bench_decimal256_builder                       1.00     82.8±1.48µs        ? ?/sec    1.04     85.8±2.66µs        ? ?/sec
bench_decimal32_builder                        1.00     55.9±0.16µs        ? ?/sec    1.01     56.7±1.85µs        ? ?/sec
bench_decimal64_builder                        1.00     45.8±0.38µs        ? ?/sec    1.00     45.8±0.21µs        ? ?/sec
bench_primitive/bench_primitive                1.03    181.1±5.88µs    21.6 GB/sec    1.00    176.0±5.75µs    22.2 GB/sec
bench_primitive/bench_string                   1.00      8.9±0.36ms   729.8 MB/sec    1.00      8.9±0.38ms   732.6 MB/sec
bench_primitive_nulls/bench_primitive_nulls    1.00  1213.4±19.73µs        ? ?/sec    1.00  1216.7±37.96µs        ? ?/sec

[alamb]

There doesn't seem to be any measurable difference in the benchmarks