Files
LocalAI/backend/cpp/ds4/generation_limits_test.cpp
T
Claudio Maradonna 30e53f8d9f fix(ds4): enforce generation boundaries (#11821)
Clamp requested generation to the usable context after prompt sync while preserving the legacy 256-token fallback for omitted limits.

Constrain each speculative MTP cycle to the remaining request budget so accepted tokens cannot advance beyond the visible output limit.

Assisted-by: Codex:gpt-5.6-sol

Signed-off-by: Claudio Maradonna <git@codeshifter.xyz>
2026-09-02 12:36:10 +02:00

93 lines
3.4 KiB
C++

// SPDX-License-Identifier: MIT
#include "generation_limits.h"
#include <cstdio>
namespace {
int failures = 0;
void check_equal(int got, int want, const char *name) {
if (got == want) return;
std::fprintf(stderr, "FAIL %s: got %d, want %d\n", name, got, want);
failures++;
}
// Mutation caught: treating omitted or negative max_tokens as unlimited instead
// of preserving DS4's legacy 256-token default.
void test_nonpositive_uses_legacy_default_when_space_permits() {
check_equal(ds4cpp::EffectiveGenerationLimit(0, 4096, 100), 256,
"zero max_tokens uses legacy default");
check_equal(ds4cpp::EffectiveGenerationLimit(-1, 4096, 100), 256,
"negative max_tokens uses legacy default");
}
// Mutation caught: applying the legacy default without clamping it to the
// post-prefill context room and reserved slot.
void test_legacy_default_is_clamped_by_context() {
check_equal(ds4cpp::EffectiveGenerationLimit(0, 300, 100), 199,
"legacy default is context-clamped");
}
// Mutation caught: allowing an explicitly large request to overrun the
// post-prefill context boundary.
void test_large_positive_limit_is_clamped_to_context() {
check_equal(ds4cpp::EffectiveGenerationLimit(32768, 32768, 100), 32667,
"large positive is context-clamped");
}
// Mutation caught: replacing every positive request with the legacy default
// rather than preserving a smaller configured limit.
void test_smaller_positive_limit_is_preserved() {
check_equal(ds4cpp::EffectiveGenerationLimit(64, 4096, 100), 64,
"smaller positive is preserved");
}
// Mutation caught: consuming the final context slot instead of reserving it as
// required by DS4's generation loop.
void test_no_usable_room_returns_zero() {
check_equal(ds4cpp::EffectiveGenerationLimit(32, 100, 99), 0,
"one remaining context slot is not usable");
}
// Mutation caught: sending the original generation limit to a later
// speculative cycle instead of subtracting tokens already produced.
void test_remaining_budget_accounts_for_produced_tokens() {
check_equal(ds4cpp::RemainingGenerationBudget(10, 4), 6,
"remaining budget subtracts produced tokens");
check_equal(ds4cpp::RemainingGenerationBudget(10, 12), 0,
"remaining budget never becomes negative");
}
// Mutation caught: giving speculative evaluation capacity beyond either the
// output budget, the draft allowance plus its first target token, or the fixed
// accepted-token buffer.
void test_speculative_capacity_obeys_all_bounds() {
check_equal(ds4cpp::SpeculativeAcceptedCapacity(3, 8, 8), 3,
"capacity respects remaining output budget");
check_equal(ds4cpp::SpeculativeAcceptedCapacity(20, 4, 8), 5,
"capacity includes one target token beyond draft allowance");
check_equal(ds4cpp::SpeculativeAcceptedCapacity(20, 8, 6), 6,
"capacity respects fixed buffer");
}
} // namespace
int main() {
test_nonpositive_uses_legacy_default_when_space_permits();
test_legacy_default_is_clamped_by_context();
test_large_positive_limit_is_clamped_to_context();
test_smaller_positive_limit_is_preserved();
test_no_usable_room_returns_zero();
test_remaining_budget_accounts_for_produced_tokens();
test_speculative_capacity_obeys_all_bounds();
if (failures == 0) {
std::fprintf(stderr, "all generation limit checks passed\n");
return 0;
}
std::fprintf(stderr, "%d check(s) failed\n", failures);
return 1;
}