diff options
Diffstat (limited to 'src/secp256k1/src/scratch.h')
-rw-r--r-- | src/secp256k1/src/scratch.h | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/src/secp256k1/src/scratch.h b/src/secp256k1/src/scratch.h index fef377af0d..77b35d126b 100644 --- a/src/secp256k1/src/scratch.h +++ b/src/secp256k1/src/scratch.h @@ -7,33 +7,36 @@ #ifndef _SECP256K1_SCRATCH_ #define _SECP256K1_SCRATCH_ -#define SECP256K1_SCRATCH_MAX_FRAMES 5 - /* The typedef is used internally; the struct name is used in the public API * (where it is exposed as a different typedef) */ typedef struct secp256k1_scratch_space_struct { - void *data[SECP256K1_SCRATCH_MAX_FRAMES]; - size_t offset[SECP256K1_SCRATCH_MAX_FRAMES]; - size_t frame_size[SECP256K1_SCRATCH_MAX_FRAMES]; - size_t frame; + /** guard against interpreting this object as other types */ + unsigned char magic[8]; + /** actual allocated data */ + void *data; + /** amount that has been allocated (i.e. `data + offset` is the next + * available pointer) */ + size_t alloc_size; + /** maximum size available to allocate */ size_t max_size; - const secp256k1_callback* error_callback; } secp256k1_scratch; static secp256k1_scratch* secp256k1_scratch_create(const secp256k1_callback* error_callback, size_t max_size); -static void secp256k1_scratch_destroy(secp256k1_scratch* scratch); +static void secp256k1_scratch_destroy(const secp256k1_callback* error_callback, secp256k1_scratch* scratch); -/** Attempts to allocate a new stack frame with `n` available bytes. Returns 1 on success, 0 on failure */ -static int secp256k1_scratch_allocate_frame(secp256k1_scratch* scratch, size_t n, size_t objects); +/** Returns an opaque object used to "checkpoint" a scratch space. Used + * with `secp256k1_scratch_apply_checkpoint` to undo allocations. */ +static size_t secp256k1_scratch_checkpoint(const secp256k1_callback* error_callback, const secp256k1_scratch* scratch); -/** Deallocates a stack frame */ -static void secp256k1_scratch_deallocate_frame(secp256k1_scratch* scratch); +/** Applies a check point received from `secp256k1_scratch_checkpoint`, + * undoing all allocations since that point. */ +static void secp256k1_scratch_apply_checkpoint(const secp256k1_callback* error_callback, secp256k1_scratch* scratch, size_t checkpoint); /** Returns the maximum allocation the scratch space will allow */ -static size_t secp256k1_scratch_max_allocation(const secp256k1_scratch* scratch, size_t n_objects); +static size_t secp256k1_scratch_max_allocation(const secp256k1_callback* error_callback, const secp256k1_scratch* scratch, size_t n_objects); /** Returns a pointer into the most recently allocated frame, or NULL if there is insufficient available space */ -static void *secp256k1_scratch_alloc(secp256k1_scratch* scratch, size_t n); +static void *secp256k1_scratch_alloc(const secp256k1_callback* error_callback, secp256k1_scratch* scratch, size_t n); #endif |