C++ remaining_buf函数代码示例

/*
 * Given a buffer containing a network byte order 16-bit integer,
 * and an arbitrary data string, copy the data string into the location
 * specified by valp.  Also return the sizes of 'valp' in bytes.
 * Adjust buffer counters.
 * NOTE: valp is set to point into a newly created buffer,
 *	the caller is responsible for calling free() on *valp
 *	if non-NULL (set to NULL on zero size buffer value)
 */
int unpackmem_malloc(char **valp, uint32_t * size_valp, Buf buffer)
{
	uint32_t ns;

	if (remaining_buf(buffer) < sizeof(ns))
		return SLURM_ERROR;

	memcpy(&ns, &buffer->head[buffer->processed], sizeof(ns));
	*size_valp = ntohl(ns);
	buffer->processed += sizeof(ns);
	if (*size_valp > MAX_PACK_MEM_LEN) {
		error("%s: Buffer to be unpacked is too large (%u > %u)",
		      __func__, *size_valp, MAX_PACK_MEM_LEN);
		return SLURM_ERROR;
	}
	else if (*size_valp > 0) {
		if (remaining_buf(buffer) < *size_valp)
			return SLURM_ERROR;
		*valp = malloc(*size_valp);
		if (*valp == NULL) {
			log_oom(__FILE__, __LINE__, __func__);
			abort();
		}
		memcpy(*valp, &buffer->head[buffer->processed],
		       *size_valp);
		buffer->processed += *size_valp;
	} else
		*valp = NULL;
	return SLURM_SUCCESS;
}

/*
 * Given a buffer containing a network byte order 16-bit integer,
 * and an arbitrary data string, copy the data string into the location
 * specified by valp.  Also return the sizes of 'valp' in bytes.
 * Adjust buffer counters.
 * NOTE: The caller is responsible for the management of valp and
 * insuring it has sufficient size
 */
int unpackmem(char *valp, uint32_t * size_valp, Buf buffer)
{
	uint32_t ns;

	if (remaining_buf(buffer) < sizeof(ns))
		return SLURM_ERROR;

	memcpy(&ns, &buffer->head[buffer->processed], sizeof(ns));
	*size_valp = ntohl(ns);
	buffer->processed += sizeof(ns);

	if (*size_valp > MAX_PACK_MEM_LEN) {
		error("%s: Buffer to be unpacked is too large (%u > %u)",
		      __func__, *size_valp, MAX_PACK_MEM_LEN);
		return SLURM_ERROR;
	}
	else if (*size_valp > 0) {
		if (remaining_buf(buffer) < *size_valp)
			return SLURM_ERROR;
		memcpy(valp, &buffer->head[buffer->processed], *size_valp);
		buffer->processed += *size_valp;
	} else
		*valp = 0;
	return SLURM_SUCCESS;
}

/*
 * Given a pointer to memory (valp) and a size (size_val), convert
 * size_val to network byte order and store at buffer followed by
 * the data at valp. Adjust buffer counters.
 */
void packmem(char *valp, uint32_t size_val, Buf buffer)
{
	uint32_t ns = htonl(size_val);

	if (size_val > MAX_PACK_MEM_LEN) {
		error("%s: Buffer to be packed is too large (%u > %u)",
		      __func__, size_val, MAX_PACK_MEM_LEN);
		return;
	}
	if (remaining_buf(buffer) < (sizeof(ns) + size_val)) {
		if ((buffer->size + size_val + BUF_SIZE) > MAX_BUF_SIZE) {
			error("%s: Buffer size limit exceeded (%u > %u)",
			      __func__, (buffer->size + size_val + BUF_SIZE),
			      MAX_BUF_SIZE);
			return;
		}
		buffer->size += (size_val + BUF_SIZE);
		xrealloc_nz(buffer->head, buffer->size);
	}

	memcpy(&buffer->head[buffer->processed], &ns, sizeof(ns));
	buffer->processed += sizeof(ns);

	if (size_val) {
		memcpy(&buffer->head[buffer->processed], valp, size_val);
		buffer->processed += size_val;
	}
}

/*
 * Given 'buffer' pointing to a network byte order 16-bit integer
 * (size) and a array of strings  store the number of strings in
 * 'size_valp' and the array of strings in valp
 * NOTE: valp is set to point into a newly created buffer,
 *	the caller is responsible for calling xfree on *valp
 *	if non-NULL (set to NULL on zero size buffer value)
 */
int unpackstr_array(char ***valp, uint32_t * size_valp, Buf buffer)
{
	int i;
	uint32_t ns;
	uint32_t uint32_tmp;

	if (remaining_buf(buffer) < sizeof(ns))
		return SLURM_ERROR;

	memcpy(&ns, &buffer->head[buffer->processed], sizeof(ns));
	*size_valp = ntohl(ns);
	buffer->processed += sizeof(ns);

	if (*size_valp > MAX_PACK_ARRAY_LEN) {
		error("%s: Buffer to be unpacked is too large (%u > %u)",
		      __func__, *size_valp, MAX_PACK_ARRAY_LEN);
		return SLURM_ERROR;
	}
	else if (*size_valp > 0) {
		*valp = xmalloc_nz(sizeof(char *) * (*size_valp + 1));
		for (i = 0; i < *size_valp; i++) {
			if (unpackmem_xmalloc(&(*valp)[i], &uint32_tmp, buffer))
				return SLURM_ERROR;
		}
		(*valp)[i] = NULL;	/* NULL terminated array so that execle */
		/*    can detect end of array */
	} else
		*valp = NULL;
	return SLURM_SUCCESS;
}

/*
 * Given a double, multiple by FLOAT_MULT and then
 * typecast to a uint64_t in host byte order, convert to network byte order
 * store in buffer, and adjust buffer counters.
 * NOTE: There is an IEEE standard format for double.
 */
void 	packdouble(double val, Buf buffer)
{
	uint64_t nl;
	union {
		double d;
		uint64_t u;
	} uval;

	 /* The 0.5 is here to round off.  We have found on systems going out
	  * more than 15 decimals will mess things up, but this corrects it. */
	uval.d =  (val * FLOAT_MULT);
	nl =  HTON_uint64(uval.u);
	if (remaining_buf(buffer) < sizeof(nl)) {
		if ((buffer->size + BUF_SIZE) > MAX_BUF_SIZE) {
			error("%s: Buffer size limit exceeded (%u > %u)",
			      __func__, (buffer->size + BUF_SIZE),
			      MAX_BUF_SIZE);
			return;
		}
		buffer->size += BUF_SIZE;
		xrealloc_nz(buffer->head, buffer->size);
	}

	memcpy(&buffer->head[buffer->processed], &nl, sizeof(nl));
	buffer->processed += sizeof(nl);
}

/*
 * Given a buffer containing a network byte order 8-bit integer,
 * store a host integer at 'valp', and adjust buffer counters.
 */
int unpack8(uint8_t * valp, Buf buffer)
{
	if (remaining_buf(buffer) < sizeof(uint8_t))
		return SLURM_ERROR;

	memcpy(valp, &buffer->head[buffer->processed], sizeof(uint8_t));
	buffer->processed += sizeof(uint8_t);
	return SLURM_SUCCESS;
}

/*
 * Given a buffer containing a network byte order 32-bit integer,
 * store a host integer at 'valp', and adjust buffer counters.
 */
int unpack32(uint32_t * valp, Buf buffer)
{
	uint32_t nl;
	if (remaining_buf(buffer) < sizeof(nl))
		return SLURM_ERROR;

	memcpy(&nl, &buffer->head[buffer->processed], sizeof(nl));
	*valp = ntohl(nl);
	buffer->processed += sizeof(nl);
	return SLURM_SUCCESS;
}

/*
 * Given a pointer to memory (valp), size (size_val), and buffer,
 * store the buffer contents into memory
 */
int unpackmem_array(char *valp, uint32_t size_valp, Buf buffer)
{
	if (remaining_buf(buffer) >= size_valp) {
		memcpy(valp, &buffer->head[buffer->processed], size_valp);
		buffer->processed += size_valp;
		return SLURM_SUCCESS;
	} else {
		*valp = 0;
		return SLURM_ERROR;
	}
}

/*
 * Given a buffer containing a network byte order 16-bit integer,
 * store a host integer at 'valp', and adjust buffer counters.
 */
int unpack16(uint16_t * valp, Buf buffer)
{
	uint16_t ns;

	if (remaining_buf(buffer) < sizeof(ns))
		return SLURM_ERROR;

	memcpy(&ns, &buffer->head[buffer->processed], sizeof(ns));
	*valp = ntohs(ns);
	buffer->processed += sizeof(ns);
	return SLURM_SUCCESS;
}

int unpack_time(time_t * valp, Buf buffer)
{
	int64_t n64;

	if (remaining_buf(buffer) < sizeof(n64))
		return SLURM_ERROR;

	memcpy(&n64, &buffer->head[buffer->processed], sizeof(n64));
	buffer->processed += sizeof(n64);
	*valp = (time_t) NTOH_int64(n64);
	return SLURM_SUCCESS;
}

/*
 * Given a buffer containing a network byte order 16-bit integer,
 * and an arbitrary data string, copy the data string into the location
 * specified by valp.  Also return the sizes of 'valp' in bytes.
 * Adjust buffer counters.
 * NOTE: The caller is responsible for the management of valp and
 * insuring it has sufficient size
 */
int unpackmem(char *valp, uint32_t * size_valp, Buf buffer)
{
	uint32_t ns;

	if (remaining_buf(buffer) < sizeof(ns))
		return SLURM_ERROR;

	memcpy(&ns, &buffer->head[buffer->processed], sizeof(ns));
	*size_valp = ntohl(ns);
	buffer->processed += sizeof(ns);

	if (*size_valp > MAX_PACK_MEM_LEN)
		return SLURM_ERROR;
	else if (*size_valp > 0) {
		if (remaining_buf(buffer) < *size_valp)
			return SLURM_ERROR;
		memcpy(valp, &buffer->head[buffer->processed], *size_valp);
		buffer->processed += *size_valp;
	} else
		*valp = 0;
	return SLURM_SUCCESS;
}

/*
 * Given a 8-bit integer in host byte order, convert to network byte order
 * store in buffer, and adjust buffer counters.
 */
void pack8(uint8_t val, Buf buffer)
{
	if (remaining_buf(buffer) < sizeof(uint8_t)) {
		if (buffer->size > (MAX_BUF_SIZE - BUF_SIZE)) {
			error("pack8: buffer size too large");
			return;
		}
		buffer->size += BUF_SIZE;
		xrealloc(buffer->head, buffer->size);
	}

	memcpy(&buffer->head[buffer->processed], &val, sizeof(uint8_t));
	buffer->processed += sizeof(uint8_t);
}

/*
 * Given a pointer to memory (valp), size (size_val), and buffer,
 * store the memory contents into the buffer
 */
void packmem_array(char *valp, uint32_t size_val, Buf buffer)
{
	if (remaining_buf(buffer) < size_val) {
		if (buffer->size > (MAX_BUF_SIZE - size_val - BUF_SIZE)) {
			error("packmem_array: buffer size too large");
			return;
		}
		buffer->size += (size_val + BUF_SIZE);
		xrealloc(buffer->head, buffer->size);
	}

	memcpy(&buffer->head[buffer->processed], valp, size_val);
	buffer->processed += size_val;
}

/*
 * Given a 8-bit integer in host byte order, convert to network byte order
 * store in buffer, and adjust buffer counters.
 */
void pack8(uint8_t val, Buf buffer)
{
	if (remaining_buf(buffer) < sizeof(uint8_t)) {
		if ((buffer->size + BUF_SIZE) > MAX_BUF_SIZE) {
			error("%s: Buffer size limit exceeded (%u > %u)",
			      __func__, (buffer->size + BUF_SIZE),
			      MAX_BUF_SIZE);
			return;
		}
		buffer->size += BUF_SIZE;
		xrealloc_nz(buffer->head, buffer->size);
	}

	memcpy(&buffer->head[buffer->processed], &val, sizeof(uint8_t));
	buffer->processed += sizeof(uint8_t);
}

/*
 * Given a time_t in host byte order, promote it to int64_t, convert to
 * network byte order, store in buffer and adjust buffer acc'd'ngly
 */
void pack_time(time_t val, Buf buffer)
{
	int64_t n64 = HTON_int64((int64_t) val);

	if (remaining_buf(buffer) < sizeof(n64)) {
		if (buffer->size > (MAX_BUF_SIZE - BUF_SIZE)) {
			error("pack_time: buffer size too large");
			return;
		}
		buffer->size += BUF_SIZE;
		xrealloc(buffer->head, buffer->size);
	}

	memcpy(&buffer->head[buffer->processed], &n64, sizeof(n64));
	buffer->processed += sizeof(n64);
}