java/src/crc8.c

   1 #include "a.h"
   2 #include "a/crc.h"
   3 #include "liba_crc8.h"
   4
   5 #undef L
   6 #define L Java_liba_crc8
   7 static struct
   8 {
   9     jmethodID New;
  10     jfieldID ctx;
  11 } L = {NULL, NULL};
  12
  13 JNIEXPORT void JNICALL Java_liba_crc8_clinit(JNIEnv *Env, jclass Cls)
  14 {
  15     jclass Nbb = (*Env)->FindClass(Env, "Ljava/nio/ByteBuffer;");
  16     L.New = (*Env)->GetStaticMethodID(Env, Nbb, "allocateDirect", "(I)Ljava/nio/ByteBuffer;");
  17     L.ctx = (*Env)->GetFieldID(Env, Cls, "ctx", "Ljava/nio/ByteBuffer;");
  18 }
  19
  20 struct crc8
  21 {
  22     a_u8 table[0x100];
  23 };
  24
  25 JNIEXPORT void JNICALL Java_liba_crc8_init(JNIEnv *Env, jobject Obj, jbyte poly, jboolean reversed)
  26 {
  27     jobject Ctx = (*Env)->CallObjectMethod(Env, Obj, L.New, (jint)sizeof(struct crc8));
  28     struct crc8 *ctx = (struct crc8 *)(*Env)->GetDirectBufferAddress(Env, Ctx);
  29     (*Env)->SetObjectField(Env, Obj, L.ctx, Ctx);
  30     reversed ? a_crc8l_init(ctx->table, (a_u8)poly)
  31              : a_crc8m_init(ctx->table, (a_u8)poly);
  32 }
  33
  34 JNIEXPORT jbyteArray JNICALL Java_liba_crc8_table(JNIEnv *Env, jobject Obj)
  35 {
  36     jobject Ctx = (*Env)->GetObjectField(Env, Obj, L.ctx);
  37     struct crc8 *ctx = (struct crc8 *)(*Env)->GetDirectBufferAddress(Env, Ctx);
  38     jbyteArray table = (*Env)->NewByteArray(Env, A_LEN(ctx->table));
  39     (*Env)->SetByteArrayRegion(Env, table, 0, A_LEN(ctx->table), (jbyte *)ctx->table);
  40     return table;
  41 }
  42
  43 JNIEXPORT jobject JNICALL Java_liba_crc8_gen(JNIEnv *Env, jobject Obj, jbyte poly, jboolean reversed)
  44 {
  45     jobject Ctx = (*Env)->GetObjectField(Env, Obj, L.ctx);
  46     struct crc8 *ctx = (struct crc8 *)(*Env)->GetDirectBufferAddress(Env, Ctx);
  47     reversed ? a_crc8l_init(ctx->table, (a_u8)poly)
  48              : a_crc8m_init(ctx->table, (a_u8)poly);
  49     return Obj;
  50 }
  51
  52 JNIEXPORT jbyte JNICALL Java_liba_crc8_eval(JNIEnv *Env, jobject Obj, jbyteArray block, jbyte value)
  53 {
  54     jobject Ctx = (*Env)->GetObjectField(Env, Obj, L.ctx);
  55     struct crc8 *ctx = (struct crc8 *)(*Env)->GetDirectBufferAddress(Env, Ctx);
  56     jsize n = (*Env)->GetArrayLength(Env, block);
  57     jbyte *p = (*Env)->GetByteArrayElements(Env, block, NULL);
  58     value = (jbyte)a_crc8(ctx->table, p, (a_size)n, (a_u8)value);
  59     (*Env)->ReleaseByteArrayElements(Env, block, p, JNI_ABORT);
  60     return value;
  61 }
  62
  63 JNIEXPORT jbyteArray JNICALL Java_liba_crc8_pack(JNIEnv *Env, jobject Obj, jbyteArray block, jbyte value)
  64 {
  65     jobject Ctx = (*Env)->GetObjectField(Env, Obj, L.ctx);
  66     struct crc8 *ctx = (struct crc8 *)(*Env)->GetDirectBufferAddress(Env, Ctx);
  67     jsize block_n = (*Env)->GetArrayLength(Env, block);
  68     jbyteArray res = (*Env)->NewByteArray(Env, block_n + 1);
  69     jbyte *block_p = (*Env)->GetByteArrayElements(Env, block, NULL);
  70     value = (jbyte)a_crc8(ctx->table, block_p, (a_size)block_n, (a_u8)value);
  71     (*Env)->SetByteArrayRegion(Env, res, 0, block_n, block_p);
  72     (*Env)->ReleaseByteArrayElements(Env, block, block_p, JNI_ABORT);
  73     (*Env)->SetByteArrayRegion(Env, res, block_n, 1, &value);
  74     return res;
  75 }