Update LMDB blittable safety checks (#32)

Co-authored-by: Zachary Levy <zachary@sunforge.is>
Reviewed-on: #32
This commit was merged in pull request #32.
This commit is contained in:
2026-06-05 21:14:16 +00:00
parent f2da356580
commit 08f8a9d0b5
2 changed files with 75 additions and 38 deletions
+4 -4
View File
@@ -68,9 +68,9 @@ main :: proc() {
db_handle: mdb.Dbi
// Put transaction
key := 7
key_val := mdb.blittable_val(&key)
key_val := mdb.pod_val(&key)
put_data := 12
put_data_val := mdb.blittable_val(&put_data)
put_data_val := mdb.pod_val(&put_data)
mdb.panic_on_err(mdb.txn_begin(environment, nil, {}, &txn_handle))
mdb.panic_on_err(mdb.dbi_open(txn_handle, nil, {}, &db_handle))
mdb.panic_on_err(mdb.put(txn_handle, db_handle, &key_val, &put_data_val, {}))
@@ -80,7 +80,7 @@ main :: proc() {
data_val: mdb.Val
mdb.panic_on_err(mdb.txn_begin(environment, nil, {}, &txn_handle))
mdb.panic_on_err(mdb.get(txn_handle, db_handle, &key_val, &data_val))
data_cpy := mdb.blittable_copy(data_val, int)
mdb.panic_on_err(mdb.txn_commit(txn_handle))
data_cpy := mdb.pod_copy(data_val, int)
mdb.txn_abort(txn_handle)
fmt.println("Get result:", data_cpy)
}
+71 -34
View File
@@ -169,58 +169,86 @@ import "core:fmt"
import "core:reflect"
import "core:sys/posix"
import b "../../basic"
// ---------------------------------------------------------------------------------------------------------------------
// ----- Added Odin Helpers ------------------------
// ---------------------------------------------------------------------------------------------------------------------
// Wrap a blittable value's bytes as an LMDB Val.
// Wrap a POD value's bytes as an LMDB Val.
// T must be a contiguous type with no indirection (no pointers, slices, strings, maps, etc.).
blittable_val :: #force_inline proc(val_ptr: ^$T) -> Val {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"blitval: type '%v' contains indirection and cannot be stored directly in LMDB",
typeid_of(T),
)
pod_val :: #force_inline proc(val_ptr: ^$T) -> Val {
when ODIN_DEBUG {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"pod_val: type '%v' contains indirection and cannot be stored directly in LMDB",
typeid_of(T),
)
}
return Val{size_of(T), val_ptr}
}
// Reads a blittable T out of the LMDB memory map by copying it into caller
// Reads a POD T out of the LMDB memory map by copying it into caller
// storage. The returned T has no lifetime tie to the transaction.
blittable_copy :: #force_inline proc(val: Val, $T: typeid) -> T {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"blitval_copy: type '%v' contains indirection and cannot be read directly from LMDB",
typeid_of(T),
)
pod_copy :: #force_inline proc(val: Val, $T: typeid) -> T {
when ODIN_DEBUG {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"pod_copy: type '%v' contains indirection and cannot be read directly from LMDB",
typeid_of(T),
)
}
when b.ODIN_BOUNDS_CHECK {
fmt.assertf(
val.size == size_of(T),
"size_of(%v) (%v) != val.size (%v)",
typeid_of(T),
size_of(T),
val.size,
)
}
return (cast(^T)val.data)^
}
// Zero-copy pointer view into the LMDB memory map as a ^T.
// Useful for large blittable types where you want to read individual fields
// Useful for large POD types where you want to read individual fields
// without copying the entire value (e.g. ptr.timestamp, ptr.flags).
// MUST NOT be written through — writes either segfault (default env mode)
// or silently corrupt the database (ENV_WRITEMAP).
// MUST NOT be retained past txn_commit, txn_abort, or any subsequent write
// operation on the same env — the pointer is invalidated.
blittable_view :: #force_inline proc(val: Val, $T: typeid) -> ^T {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"blitval_view: type '%v' contains indirection and cannot be viewed directly from LMDB",
typeid_of(T),
)
pod_view :: #force_inline proc(val: Val, $T: typeid) -> ^T {
when ODIN_DEBUG {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"pod_view: type '%v' contains indirection and cannot be viewed directly from LMDB",
typeid_of(T),
)
}
when b.ODIN_BOUNDS_CHECK {
fmt.assertf(
val.size == size_of(T),
"size_of(%v) (%v) != val.size (%v)",
typeid_of(T),
size_of(T),
val.size,
)
}
return cast(^T)val.data
}
// Wrap a slice of blittable elements as an LMDB Val for use with put/get.
// Wrap a slice of POD elements as an LMDB Val for use with put/get.
// T must be a contiguous type with no indirection.
// The caller's slice must remain valid (not freed, not resized) for the
// duration of the put call that consumes this Val.
slice_val :: #force_inline proc(s: []$T) -> Val {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"slice_val: element type '%v' contains indirection and cannot be stored directly in LMDB",
typeid_of(T),
)
pod_slice_val :: #force_inline proc(s: []$T) -> Val {
when ODIN_DEBUG {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"pod_slice_val: element type '%v' contains indirection and cannot be stored directly in LMDB",
typeid_of(T),
)
}
return Val{uint(len(s) * size_of(T)), raw_data(s)}
}
@@ -231,12 +259,21 @@ slice_val :: #force_inline proc(s: []$T) -> Val {
// MUST be copied (e.g. slice.clone) if it needs to outlive the current
// transaction; the view is invalidated by txn_commit, txn_abort, or any
// subsequent write operation on the same env.
slice_view :: #force_inline proc(val: Val, $T: typeid) -> []T {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"slice_view: element type '%v' contains indirection and cannot be read directly from LMDB",
typeid_of(T),
)
pod_slice_view :: #force_inline proc(val: Val, $T: typeid) -> []T {
when ODIN_DEBUG {
fmt.assertf(
reflect.has_no_indirections(type_info_of(T)),
"pod_slice_view: element type '%v' contains indirection and cannot be read directly from LMDB",
typeid_of(T),
)
fmt.assertf(
val.size % size_of(T) == 0,
"pod_slice_view: val.size (%v) is not a multiple of size_of(%v) (%v)",
val.size,
typeid_of(T),
size_of(T),
)
}
return (cast([^]T)val.data)[:val.size / size_of(T)]
}