Idris2/support/refc/buffer.c
2021-06-14 15:06:44 +01:00

141 lines
3.2 KiB
C

#include "buffer.h"
#include <sys/stat.h>
#include <string.h>
typedef struct {
int size;
uint8_t data[];
} Buffer;
void* newBuffer(int bytes) {
size_t size = sizeof(Buffer) + bytes*sizeof(uint8_t);
Buffer* buf = malloc(size);
if (buf == NULL) {
return NULL;
}
buf->size = bytes;
// memset(buf->data, 0, bytes);
return (void*)buf;
}
void freeBuffer(void* buf) {
free(buf);
}
void copyBuffer(void* from, int start, int len,
void* to, int loc) {
Buffer* bfrom = from;
Buffer* bto = to;
if (loc >= 0 && loc+len <= bto->size) {
memcpy(bto->data + loc, bfrom->data + start, len);
}
}
int getBufferSize(void* buffer) {
return ((Buffer*)buffer)->size;
}
void setBufferByte(void* buffer, int loc, int byte) {
Buffer* b = buffer;
if (loc >= 0 && loc < b->size) {
b->data[loc] = byte;
}
}
void setBufferInt(void* buffer, int loc, int64_t val) {
Buffer* b = buffer;
if (loc >= 0 && loc+3 < b->size) {
b->data[loc ] = val & 0xff;
b->data[loc+1] = (val >> 8) & 0xff;
b->data[loc+2] = (val >> 16) & 0xff;
b->data[loc+3] = (val >> 24) & 0xff;
b->data[loc+4] = (val >> 32) & 0xff;
b->data[loc+5] = (val >> 40) & 0xff;
b->data[loc+6] = (val >> 48) & 0xff;
b->data[loc+7] = (val >> 56) & 0xff;
}
}
void setBufferDouble(void* buffer, int loc, double val) {
Buffer* b = buffer;
// I am not proud of this
if (loc >= 0 && loc + sizeof(double) <= b->size) {
unsigned char* c = (unsigned char*)(& val);
int i;
for (i = 0; i < sizeof(double); ++i) {
b->data[loc+i] = c[i];
}
}
}
void setBufferString(void* buffer, int loc, char* str) {
Buffer* b = buffer;
int len = strlen(str);
if (loc >= 0 && loc+len <= b->size) {
memcpy((b->data)+loc, str, len);
}
}
size_t writeBufferData(FILE* h, void* buffer, size_t loc, size_t len) {
Buffer* b = buffer;
return fwrite(b->data + loc, sizeof(uint8_t), len, h);
}
uint8_t getBufferByte(void* buffer, int loc) {
Buffer* b = buffer;
if (loc >= 0 && loc < b->size) {
return b->data[loc];
} else {
return 0;
}
}
int64_t getBufferInt(void* buffer, int loc) {
Buffer* b = buffer;
if (loc >= 0 && loc+7 < b->size) {
int64_t result = 0;
for (size_t i=0; i<8; i++) {
result |= b->data[loc + i] << (8 * i);
}
return result;
} else {
return 0;
}
}
double getBufferDouble(void* buffer, int loc) {
Buffer* b = buffer;
double d;
// I am even less proud of this
unsigned char *c = (unsigned char*)(& d);
if (loc >= 0 && loc + sizeof(double) <= b->size) {
int i;
for (i = 0; i < sizeof(double); ++i) {
c[i] = b->data[loc+i];
}
return d;
}
else {
return 0;
}
}
char* getBufferString(void* buffer, int loc, int len) {
Buffer* b = buffer;
char * s = (char*)(b->data + loc);
char * rs = malloc(len + 1);
strncpy(rs, s, len);
rs[len] = '\0';
return rs;
}
size_t readBufferData(FILE* h, void* buffer, size_t loc, size_t max) {
Buffer* b = buffer;
return fread(b->data + loc, sizeof(uint8_t), max, h);
}