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#include <stdint.h>
#include <stddef.h>
#ifdef _OPENMP
#include <omp.h>
#endif
#include "libbase64.h"
#include "tables/tables.h"
#include "codecs.h"
#include "env.h"
// These static function pointers are initialized once when the library is
// first used, and remain in use for the remaining lifetime of the program.
// The idea being that CPU features don't change at runtime.
static struct codec codec = { NULL, NULL };
void
base64_stream_encode_init (struct base64_state *state, int flags)
{
// If any of the codec flags are set, redo choice:
if (codec.enc == NULL || flags & 0xFF) {
codec_choose(&codec, flags);
}
state->eof = 0;
state->bytes = 0;
state->carry = 0;
state->flags = flags;
}
void
base64_stream_encode
( struct base64_state *state
, const char *src
, size_t srclen
, char *out
, size_t *outlen
)
{
codec.enc(state, src, srclen, out, outlen);
}
void
base64_stream_encode_final
( struct base64_state *state
, char *out
, size_t *outlen
)
{
uint8_t *o = (uint8_t *)out;
if (state->bytes == 1) {
*o++ = base64_table_enc_6bit[state->carry];
*o++ = '=';
*o++ = '=';
*outlen = 3;
return;
}
if (state->bytes == 2) {
*o++ = base64_table_enc_6bit[state->carry];
*o++ = '=';
*outlen = 2;
return;
}
*outlen = 0;
}
void
base64_stream_decode_init (struct base64_state *state, int flags)
{
// If any of the codec flags are set, redo choice:
if (codec.dec == NULL || flags & 0xFFFF) {
codec_choose(&codec, flags);
}
state->eof = 0;
state->bytes = 0;
state->carry = 0;
state->flags = flags;
}
int
base64_stream_decode
( struct base64_state *state
, const char *src
, size_t srclen
, char *out
, size_t *outlen
)
{
return codec.dec(state, src, srclen, out, outlen);
}
#ifdef _OPENMP
// Due to the overhead of initializing OpenMP and creating a team of
// threads, we require the data length to be larger than a threshold:
#define OMP_THRESHOLD 20000
// Conditionally include OpenMP-accelerated codec implementations:
#include "lib_openmp.c"
#endif
void
base64_encode
( const char *src
, size_t srclen
, char *out
, size_t *outlen
, int flags
)
{
size_t s;
size_t t;
struct base64_state state;
#ifdef _OPENMP
if (srclen >= OMP_THRESHOLD) {
base64_encode_openmp(src, srclen, out, outlen, flags);
return;
}
#endif
// Init the stream reader:
base64_stream_encode_init(&state, flags);
// Feed the whole string to the stream reader:
base64_stream_encode(&state, src, srclen, out, &s);
// Finalize the stream by writing trailer if any:
base64_stream_encode_final(&state, out + s, &t);
// Final output length is stream length plus tail:
*outlen = s + t;
}
int
base64_decode
( const char *src
, size_t srclen
, char *out
, size_t *outlen
, int flags
)
{
int ret;
struct base64_state state;
#ifdef _OPENMP
if (srclen >= OMP_THRESHOLD) {
return base64_decode_openmp(src, srclen, out, outlen, flags);
}
#endif
// Init the stream reader:
base64_stream_decode_init(&state, flags);
// Feed the whole string to the stream reader:
ret = base64_stream_decode(&state, src, srclen, out, outlen);
// If when decoding a whole block, we're still waiting for input then fail:
if (ret && (state.bytes == 0)) {
return ret;
}
return 0;
}
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