test_store_pragmas.c

/*
 * test_store_pragmas.c — Tests for SQLite pragma resolution.
 *
 * Validates that the CBM_SQLITE_MMAP_SIZE env var controls the mmap_size
 * pragma applied to on-disk stores. Default behavior (env unset) must
 * remain 64 MB. Setting the env to 0 disables memory-mapped I/O so
 * concurrent processes that truncate the DB file under a sibling's live
 * mapping return SQLITE_IOERR instead of crashing the process with SIGBUS.
 */
#include "../src/foundation/compat.h"
#include "test_framework.h"
#include "test_helpers.h"
#include <store/store.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static void clear_mmap_env(void) {
    unsetenv("CBM_SQLITE_MMAP_SIZE");
}

TEST(mmap_size_default_when_unset) {
    clear_mmap_env();
    ASSERT_EQ(cbm_store_resolve_mmap_size(), 67108864LL);
    PASS();
}

TEST(mmap_size_zero_disables_mmap) {
    setenv("CBM_SQLITE_MMAP_SIZE", "0", 1);
    ASSERT_EQ(cbm_store_resolve_mmap_size(), 0LL);
    clear_mmap_env();
    PASS();
}

TEST(mmap_size_explicit_value) {
    setenv("CBM_SQLITE_MMAP_SIZE", "1048576", 1);
    ASSERT_EQ(cbm_store_resolve_mmap_size(), 1048576LL);
    clear_mmap_env();
    PASS();
}

TEST(mmap_size_negative_clamped_to_zero) {
    setenv("CBM_SQLITE_MMAP_SIZE", "-1", 1);
    ASSERT_EQ(cbm_store_resolve_mmap_size(), 0LL);
    clear_mmap_env();
    PASS();
}

TEST(mmap_size_garbage_falls_back_to_default) {
    setenv("CBM_SQLITE_MMAP_SIZE", "not-a-number", 1);
    ASSERT_EQ(cbm_store_resolve_mmap_size(), 67108864LL);
    clear_mmap_env();
    PASS();
}

TEST(mmap_size_partial_garbage_falls_back_to_default) {
    setenv("CBM_SQLITE_MMAP_SIZE", "123abc", 1);
    ASSERT_EQ(cbm_store_resolve_mmap_size(), 67108864LL);
    clear_mmap_env();
    PASS();
}

/* Integration smoke: opening a file-backed store with mmap_size=0 must
 * succeed. Proves the resolver is wired through configure_pragmas(). */
TEST(store_open_with_mmap_disabled) {
    setenv("CBM_SQLITE_MMAP_SIZE", "0", 1);
    char tmp_path[256];
    snprintf(tmp_path, sizeof(tmp_path), "/tmp/cbm_test_pragmas_%d.db", (int)getpid());
    unlink(tmp_path);

    cbm_store_t *s = cbm_store_open_path(tmp_path);
    ASSERT(s != NULL);
    cbm_store_close(s);

    unlink(tmp_path);
    /* WAL/SHM siblings created by the open */
    char tmp_wal[300];
    char tmp_shm[300];
    snprintf(tmp_wal, sizeof(tmp_wal), "%s-wal", tmp_path);
    snprintf(tmp_shm, sizeof(tmp_shm), "%s-shm", tmp_path);
    unlink(tmp_wal);
    unlink(tmp_shm);

    clear_mmap_env();
    PASS();
}

SUITE(store_pragmas) {
    RUN_TEST(mmap_size_default_when_unset);
    RUN_TEST(mmap_size_zero_disables_mmap);
    RUN_TEST(mmap_size_explicit_value);
    RUN_TEST(mmap_size_negative_clamped_to_zero);
    RUN_TEST(mmap_size_garbage_falls_back_to_default);
    RUN_TEST(mmap_size_partial_garbage_falls_back_to_default);
    RUN_TEST(store_open_with_mmap_disabled);
}