用户态协议栈05—架构优化

优化部分

  • 添加了in和out两个环形缓冲区，收到数据包后添加到in队列；经过消费者线程处理之后，将需要发送的数据包添加到out队列。
  • 添加数据包解析线程（消费者线程），架构分层

#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_mbuf.h>
#include <rte_malloc.h>
#include <rte_timer.h>
#include <rte_ring.h>

#include <stdio.h>
#include <arpa/inet.h>

#include "arp.h"

#define ENABLE_SEND		1
#define ENABLE_ARP		1
#define ENABLE_ICMP		1
#define ENABLE_ARP_REPLY	1

#define ENABLE_DEBUG		1

#define ENABLE_TIMER		1


#define NUM_MBUFS (4096-1)

#define BURST_SIZE	32

#define RING_SIZE	1024

#define TIMER_RESOLUTION_CYCLES 120000000000ULL // 10ms * 1000 = 10s * 6

struct inout_ring {

	struct rte_ring* in;
	struct rte_ring* out;
};

static struct inout_ring* ioInst = NULL;

static struct inout_ring* inout_ring_instance(void) {

	if(ioInst == NULL) {

		ioInst = rte_malloc("inout ring", sizeof(struct inout_ring), 0);
		memset(ioInst, 0, sizeof(struct inout_ring));
	}

	return ioInst;
}


#if ENABLE_SEND

#define MAKE_IPV4_ADDR(a, b, c, d) (a + (b<<8) + (c<<16) + (d<<24))

static uint32_t gLocalIp = MAKE_IPV4_ADDR(192, 168, 1, 184);

static uint32_t gSrcIp; //
static uint32_t gDstIp;

static uint8_t gSrcMac[RTE_ETHER_ADDR_LEN];
static uint8_t gDstMac[RTE_ETHER_ADDR_LEN];

static uint16_t gSrcPort;
static uint16_t gDstPort;

#endif

#if ENABLE_ARP_REPLY

static uint8_t gDefaultArpMac[RTE_ETHER_ADDR_LEN] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

#endif

int gDpdkPortId = 0;

static const struct rte_eth_conf port_conf_default = {
	.rxmode = {.max_rx_pkt_len = RTE_ETHER_MAX_LEN }
};

static void ng_init_port(struct rte_mempool *mbuf_pool) {

	uint16_t nb_sys_ports= rte_eth_dev_count_avail(); //
	if (nb_sys_ports == 0) {
		rte_exit(EXIT_FAILURE, "No Supported eth found\n");
	}

	struct rte_eth_dev_info dev_info;
	rte_eth_dev_info_get(gDpdkPortId, &dev_info); //
	
	const int num_rx_queues = 1;
	const int num_tx_queues = 1;
	struct rte_eth_conf port_conf = port_conf_default;
	rte_eth_dev_configure(gDpdkPortId, num_rx_queues, num_tx_queues, &port_conf);


	if (rte_eth_rx_queue_setup(gDpdkPortId, 0 , 1024, 
		rte_eth_dev_socket_id(gDpdkPortId),NULL, mbuf_pool) < 0) {

		rte_exit(EXIT_FAILURE, "Could not setup RX queue\n");

	}
	
#if ENABLE_SEND
	struct rte_eth_txconf txq_conf = dev_info.default_txconf;
	txq_conf.offloads = port_conf.rxmode.offloads;
	if (rte_eth_tx_queue_setup(gDpdkPortId, 0 , 1024, 
		rte_eth_dev_socket_id(gDpdkPortId), &txq_conf) < 0) {
		
		rte_exit(EXIT_FAILURE, "Could not setup TX queue\n");
		
	}
#endif

	if (rte_eth_dev_start(gDpdkPortId) < 0 ) {
		rte_exit(EXIT_FAILURE, "Could not start\n");
	}
}


static int ng_encode_udp_pkt(uint8_t *msg, unsigned char *data, uint16_t total_len) {

	// encode 

	// 1 ethhdr
	struct rte_ether_hdr *eth = (struct rte_ether_hdr *)msg;
	rte_memcpy(eth->s_addr.addr_bytes, gSrcMac, RTE_ETHER_ADDR_LEN);
	rte_memcpy(eth->d_addr.addr_bytes, gDstMac, RTE_ETHER_ADDR_LEN);
	eth->ether_type = htons(RTE_ETHER_TYPE_IPV4);
	

	// 2 iphdr 
	struct rte_ipv4_hdr *ip = (struct rte_ipv4_hdr *)(msg + sizeof(struct rte_ether_hdr));
	ip->version_ihl = 0x45;
	ip->type_of_service = 0;
	ip->total_length = htons(total_len - sizeof(struct rte_ether_hdr));
	ip->packet_id = 0;
	ip->fragment_offset = 0;
	ip->time_to_live = 64; // ttl = 64
	ip->next_proto_id = IPPROTO_UDP;
	ip->src_addr = gSrcIp;
	ip->dst_addr = gDstIp;
	
	ip->hdr_checksum = 0;
	ip->hdr_checksum = rte_ipv4_cksum(ip);

	// 3 udphdr 

	struct rte_udp_hdr *udp = (struct rte_udp_hdr *)(msg + sizeof(struct rte_ether_hdr) + sizeof(struct rte_ipv4_hdr));
	udp->src_port = gSrcPort;
	udp->dst_port = gDstPort;
	uint16_t udplen = total_len - sizeof(struct rte_ether_hdr) - sizeof(struct rte_ipv4_hdr);
	udp->dgram_len = htons(udplen);

	rte_memcpy((uint8_t*)(udp+1), data, udplen);

	udp->dgram_cksum = 0;
	udp->dgram_cksum = rte_ipv4_udptcp_cksum(ip, udp);

	struct in_addr addr;
	addr.s_addr = gSrcIp;
	printf(" --> src: %s:%d, ", inet_ntoa(addr), ntohs(gSrcPort));

	addr.s_addr = gDstIp;
	printf("dst: %s:%d\n", inet_ntoa(addr), ntohs(gDstPort));

	return 0;
}


static struct rte_mbuf * ng_send_udp(struct rte_mempool *mbuf_pool, uint8_t *data, uint16_t length) {

	// mempool --> mbuf

	const unsigned total_len = length + 42;

	struct rte_mbuf *mbuf = rte_pktmbuf_alloc(mbuf_pool);
	if (!mbuf) {
		rte_exit(EXIT_FAILURE, "rte_pktmbuf_alloc\n");
	}
	mbuf->pkt_len = total_len;
	mbuf->data_len = total_len;

	uint8_t *pktdata = rte_pktmbuf_mtod(mbuf, uint8_t*);

	ng_encode_udp_pkt(pktdata, data, total_len);

	return mbuf;

}



#if ENABLE_ARP


static int ng_encode_arp_pkt(uint8_t *msg, uint16_t opcode, uint8_t *dst_mac, uint32_t sip, uint32_t dip) {

	// 1 ethhdr
	struct rte_ether_hdr *eth = (struct rte_ether_hdr *)msg;
	rte_memcpy(eth->s_addr.addr_bytes, gSrcMac, RTE_ETHER_ADDR_LEN);
	if (!strncmp((const char *)dst_mac, (const char *)gDefaultArpMac, RTE_ETHER_ADDR_LEN)) {
		uint8_t mac[RTE_ETHER_ADDR_LEN] = {0x0};
		rte_memcpy(eth->d_addr.addr_bytes, mac, RTE_ETHER_ADDR_LEN);
	} else {
		rte_memcpy(eth->d_addr.addr_bytes, dst_mac, RTE_ETHER_ADDR_LEN);
	}
	eth->ether_type = htons(RTE_ETHER_TYPE_ARP);

	// 2 arp 
	struct rte_arp_hdr *arp = (struct rte_arp_hdr *)(eth + 1);
	arp->arp_hardware = htons(1);
	arp->arp_protocol = htons(RTE_ETHER_TYPE_IPV4);
	arp->arp_hlen = RTE_ETHER_ADDR_LEN;
	arp->arp_plen = sizeof(uint32_t);
	arp->arp_opcode = htons(opcode);

	rte_memcpy(arp->arp_data.arp_sha.addr_bytes, gSrcMac, RTE_ETHER_ADDR_LEN);
	rte_memcpy( arp->arp_data.arp_tha.addr_bytes, dst_mac, RTE_ETHER_ADDR_LEN);

	arp->arp_data.arp_sip = sip;
	arp->arp_data.arp_tip = dip;
	
	return 0;

}

static struct rte_mbuf *ng_send_arp(struct rte_mempool *mbuf_pool, uint16_t opcode, uint8_t *dst_mac, uint32_t sip, uint32_t dip) {

	const unsigned total_length = sizeof(struct rte_ether_hdr) + sizeof(struct rte_arp_hdr);

	struct rte_mbuf *mbuf = rte_pktmbuf_alloc(mbuf_pool);
	if (!mbuf) {
		rte_exit(EXIT_FAILURE, "rte_pktmbuf_alloc\n");
	}

	mbuf->pkt_len = total_length;
	mbuf->data_len = total_length;

	uint8_t *pkt_data = rte_pktmbuf_mtod(mbuf, uint8_t *);
	ng_encode_arp_pkt(pkt_data, opcode, dst_mac, sip, dip);

	return mbuf;
}

#endif


#if ENABLE_ICMP


static uint16_t ng_checksum(uint16_t *addr, int count) {

	register long sum = 0;

	while (count > 1) {

		sum += *(unsigned short*)addr++;
		count -= 2;
	
	}

	if (count > 0) {
		sum += *(unsigned char *)addr;
	}

	while (sum >> 16) {
		sum = (sum & 0xffff) + (sum >> 16);
	}

	return ~sum;
}

static int ng_encode_icmp_pkt(uint8_t *msg, uint8_t *dst_mac,
		uint32_t sip, uint32_t dip, uint16_t id, uint16_t seqnb) {

	// 1 ether
	struct rte_ether_hdr *eth = (struct rte_ether_hdr *)msg;
	rte_memcpy(eth->s_addr.addr_bytes, gSrcMac, RTE_ETHER_ADDR_LEN);
	rte_memcpy(eth->d_addr.addr_bytes, dst_mac, RTE_ETHER_ADDR_LEN);
	eth->ether_type = htons(RTE_ETHER_TYPE_IPV4);

	// 2 ip
	struct rte_ipv4_hdr *ip = (struct rte_ipv4_hdr *)(msg + sizeof(struct rte_ether_hdr));
	ip->version_ihl = 0x45;
	ip->type_of_service = 0;
	ip->total_length = htons(sizeof(struct rte_ipv4_hdr) + sizeof(struct rte_icmp_hdr));
	ip->packet_id = 0;
	ip->fragment_offset = 0;
	ip->time_to_live = 64; // ttl = 64
	ip->next_proto_id = IPPROTO_ICMP;
	ip->src_addr = sip;
	ip->dst_addr = dip;
	
	ip->hdr_checksum = 0;
	ip->hdr_checksum = rte_ipv4_cksum(ip);

	// 3 icmp 
	struct rte_icmp_hdr *icmp = (struct rte_icmp_hdr *)(msg + sizeof(struct rte_ether_hdr) + sizeof(struct rte_ipv4_hdr));
	icmp->icmp_type = RTE_IP_ICMP_ECHO_REPLY;
	icmp->icmp_code = 0;
	icmp->icmp_ident = id;
	icmp->icmp_seq_nb = seqnb;

	icmp->icmp_cksum = 0;
	icmp->icmp_cksum = ng_checksum((uint16_t*)icmp, sizeof(struct rte_icmp_hdr));

	return 0;
}


static struct rte_mbuf *ng_send_icmp(struct rte_mempool *mbuf_pool, uint8_t *dst_mac,
		uint32_t sip, uint32_t dip, uint16_t id, uint16_t seqnb) {

	const unsigned total_length = sizeof(struct rte_ether_hdr) + sizeof(struct rte_ipv4_hdr) + sizeof(struct rte_icmp_hdr);

	struct rte_mbuf *mbuf = rte_pktmbuf_alloc(mbuf_pool);
	if (!mbuf) {
		rte_exit(EXIT_FAILURE, "rte_pktmbuf_alloc\n");
	}

	
	mbuf->pkt_len = total_length;
	mbuf->data_len = total_length;

	uint8_t *pkt_data = rte_pktmbuf_mtod(mbuf, uint8_t *);
	ng_encode_icmp_pkt(pkt_data, dst_mac, sip, dip, id, seqnb);

	return mbuf;

}


#endif

static void 
print_ethaddr(const char *name, const struct rte_ether_addr *eth_addr)
{
	char buf[RTE_ETHER_ADDR_FMT_SIZE];
	rte_ether_format_addr(buf, RTE_ETHER_ADDR_FMT_SIZE, eth_addr);
	printf("%s%s", name, buf);
}


#if ENABLE_TIMER

static void
arp_request_timer_cb(__attribute__((unused)) struct rte_timer *tim,
	   void *arg) {

	struct rte_mempool *mbuf_pool = (struct rte_mempool *)arg;

#if 0
	struct rte_mbuf *arpbuf = ng_send_arp(mbuf_pool, RTE_ARP_OP_REQUEST, ahdr->arp_data.arp_sha.addr_bytes, 
		ahdr->arp_data.arp_tip, ahdr->arp_data.arp_sip);

	rte_eth_tx_burst(gDpdkPortId, 0, &arpbuf, 1);
	rte_pktmbuf_free(arpbuf);

#endif
	
	int i = 0;
	for (i = 1;i <= 254;i ++) {

		uint32_t dstip = (gLocalIp & 0x00FFFFFF) | (0xFF000000 & (i << 24));

		struct in_addr addr;
		addr.s_addr = dstip;
		printf("arp ---> src: %s \n", inet_ntoa(addr));

		struct rte_mbuf *arpbuf = NULL;
		uint8_t *dstmac = ng_get_dst_macaddr(dstip);
		if (dstmac == NULL) {

			arpbuf = ng_send_arp(mbuf_pool, RTE_ARP_OP_REQUEST, gDefaultArpMac, gLocalIp, dstip);
		
		} else {

			arpbuf = ng_send_arp(mbuf_pool, RTE_ARP_OP_REQUEST, dstmac, gLocalIp, dstip);
		}

		rte_eth_tx_burst(gDpdkPortId, 0, &arpbuf, 1);
		rte_pktmbuf_free(arpbuf);
		
	}
	
}


#endif

static int pkt_process(void* arg) {

	struct rte_mempool* mbuf_pool = (struct rte_mempool*)arg;
	struct inout_ring* ring = inout_ring_instance();

	while(1) {

		struct rte_mbuf *mbufs[BURST_SIZE];
		unsigned num_recvd = rte_ring_mc_dequeue_burst(ring->in, (void**)mbufs, BURST_SIZE, NULL);

		unsigned i = 0;
		for (i = 0;i < num_recvd;i++) {

			struct rte_ether_hdr *ehdr = rte_pktmbuf_mtod(mbufs[i], struct rte_ether_hdr*);

#if ENABLE_ARP

			if (ehdr->ether_type == rte_cpu_to_be_16(RTE_ETHER_TYPE_ARP)) {

				struct rte_arp_hdr *ahdr = rte_pktmbuf_mtod_offset(mbufs[i], 
					struct rte_arp_hdr *, sizeof(struct rte_ether_hdr));

				
				struct in_addr addr;
				addr.s_addr = ahdr->arp_data.arp_tip;
				printf("arp ---> src: %s ", inet_ntoa(addr));

				addr.s_addr = gLocalIp;
				printf(" local: %s \n", inet_ntoa(addr));

				if (ahdr->arp_data.arp_tip == gLocalIp) {

					if (ahdr->arp_opcode == rte_cpu_to_be_16(RTE_ARP_OP_REQUEST)) {

						printf("arp --> request\n");

						struct rte_mbuf *arpbuf = ng_send_arp(mbuf_pool, RTE_ARP_OP_REPLY, ahdr->arp_data.arp_sha.addr_bytes, 
							ahdr->arp_data.arp_tip, ahdr->arp_data.arp_sip);

						//rte_eth_tx_burst(gDpdkPortId, 0, &arpbuf, 1);
						//rte_pktmbuf_free(arpbuf);
						rte_ring_mp_enqueue_burst(ring->out, (void**)&arpbuf, 1, NULL);

					} else if (ahdr->arp_opcode == rte_cpu_to_be_16(RTE_ARP_OP_REPLY)) {

						printf("arp --> reply\n");

						struct arp_table *table = arp_table_instance();

						uint8_t *hwaddr = ng_get_dst_macaddr(ahdr->arp_data.arp_sip);
						if (hwaddr == NULL) {

							struct arp_entry *entry = rte_malloc("arp_entry",sizeof(struct arp_entry), 0);
							if (entry) {
								memset(entry, 0, sizeof(struct arp_entry));

								entry->ip = ahdr->arp_data.arp_sip;
								rte_memcpy(entry->hwaddr, ahdr->arp_data.arp_sha.addr_bytes, RTE_ETHER_ADDR_LEN);
								entry->type = 0;
								
								LL_ADD(entry, table->entries);
								table->count ++;
							}

						}
#if ENABLE_DEBUG
						struct arp_entry *iter;
						for (iter = table->entries; iter != NULL; iter = iter->next) {
					
							struct in_addr addr;
							addr.s_addr = iter->ip;

							print_ethaddr("arp table --> mac: ", (struct rte_ether_addr *)iter->hwaddr);
								
							printf(" ip: %s \n", inet_ntoa(addr));
					
						}
#endif
						rte_pktmbuf_free(mbufs[i]);
					}
				
					continue;
				} 
			}
#endif

			if (ehdr->ether_type != rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4)) {
				continue;
			}

			struct rte_ipv4_hdr *iphdr =  rte_pktmbuf_mtod_offset(mbufs[i], struct rte_ipv4_hdr *, 
				sizeof(struct rte_ether_hdr));
			
			if (iphdr->next_proto_id == IPPROTO_UDP) {

				struct rte_udp_hdr *udphdr = (struct rte_udp_hdr *)(iphdr + 1);

#if ENABLE_SEND //

				rte_memcpy(gDstMac, ehdr->s_addr.addr_bytes, RTE_ETHER_ADDR_LEN);
				
				rte_memcpy(&gSrcIp, &iphdr->dst_addr, sizeof(uint32_t));
				rte_memcpy(&gDstIp, &iphdr->src_addr, sizeof(uint32_t));

				rte_memcpy(&gSrcPort, &udphdr->dst_port, sizeof(uint16_t));
				rte_memcpy(&gDstPort, &udphdr->src_port, sizeof(uint16_t));

#endif

				uint16_t length = ntohs(udphdr->dgram_len);
				*((char*)udphdr + length) = '\0';

				struct in_addr addr;
				addr.s_addr = iphdr->src_addr;
				printf("src: %s:%d, ", inet_ntoa(addr), ntohs(udphdr->src_port));

				addr.s_addr = iphdr->dst_addr;
				printf("dst: %s:%d, %s\n", inet_ntoa(addr), ntohs(udphdr->dst_port), 
					(char *)(udphdr+1));

#if ENABLE_SEND

				struct rte_mbuf *txbuf = ng_send_udp(mbuf_pool, (uint8_t *)(udphdr+1), length);
				//rte_eth_tx_burst(gDpdkPortId, 0, &txbuf, 1);
				//rte_pktmbuf_free(txbuf);
				rte_ring_mp_enqueue_burst(ring->out, (void**)&txbuf, 1, NULL);
				
#endif

				rte_pktmbuf_free(mbufs[i]);
			}

#if ENABLE_ICMP

			if (iphdr->next_proto_id == IPPROTO_ICMP) {

				struct rte_icmp_hdr *icmphdr = (struct rte_icmp_hdr *)(iphdr + 1);

				
				struct in_addr addr;
				addr.s_addr = iphdr->src_addr;
				printf("icmp ---> src: %s ", inet_ntoa(addr));

				
				if (icmphdr->icmp_type == RTE_IP_ICMP_ECHO_REQUEST) {

					addr.s_addr = iphdr->dst_addr;
					printf(" local: %s , type : %d\n", inet_ntoa(addr), icmphdr->icmp_type);
				

					struct rte_mbuf *txbuf = ng_send_icmp(mbuf_pool, ehdr->s_addr.addr_bytes,
						iphdr->dst_addr, iphdr->src_addr, icmphdr->icmp_ident, icmphdr->icmp_seq_nb);

					//rte_eth_tx_burst(gDpdkPortId, 0, &txbuf, 1);
					//rte_pktmbuf_free(txbuf);
					rte_ring_mp_enqueue_burst(ring->out, (void**)&txbuf, 1, NULL);

					rte_pktmbuf_free(mbufs[i]);
				}
				

			}


#endif
			
		}
	}


	return 0;
}

int main(int argc, char *argv[]) {

	if (rte_eal_init(argc, argv) < 0) {
		rte_exit(EXIT_FAILURE, "Error with EAL init\n");
		
	}

	struct rte_mempool *mbuf_pool = rte_pktmbuf_pool_create("mbuf pool", NUM_MBUFS,
		0, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
	if (mbuf_pool == NULL) {
		rte_exit(EXIT_FAILURE, "Could not create mbuf pool\n");
	}

	ng_init_port(mbuf_pool);

	rte_eth_macaddr_get(gDpdkPortId, (struct rte_ether_addr *)gSrcMac);

#if ENABLE_TIMER

	rte_timer_subsystem_init();

	struct rte_timer arp_timer;
	rte_timer_init(&arp_timer);

	uint64_t hz = rte_get_timer_hz();
	unsigned lcore_id = rte_lcore_id();
	rte_timer_reset(&arp_timer, hz, PERIODICAL, lcore_id, arp_request_timer_cb, mbuf_pool);

#endif
	struct inout_ring* ring = inout_ring_instance();

	if(ring == NULL)
		rte_exit(EXIT_FAILURE, "Could not init ioInst\n");
	if(ring->in == NULL)
		ring->in = rte_ring_create("ring in", RING_SIZE, rte_socket_id(), RING_F_SC_DEQ | RING_F_SP_ENQ);
	if(ring->out == NULL)
		ring->out = rte_ring_create("ring out", RING_SIZE, rte_socket_id(), RING_F_SC_DEQ | RING_F_SP_ENQ);

	rte_eal_remote_launch(pkt_process, mbuf_pool, rte_get_next_lcore(lcore_id, 1, 0));

	while (1) {

		struct rte_mbuf* rx[BURST_SIZE];
		unsigned nb_recv = rte_eth_rx_burst(gDpdkPortId, 0, rx, BURST_SIZE);

		if(nb_recv > BURST_SIZE) {

			rte_exit(EXIT_FAILURE, "Error receiving from eth\n");
		}
		else {

			rte_ring_sp_enqueue_burst(ring->in, (void**)rx, nb_recv, NULL);
		}

		struct rte_mbuf* tx[BURST_SIZE];
		unsigned nb_send = rte_ring_sc_dequeue_burst(ring->out, (void**)tx, BURST_SIZE, NULL);
		if(nb_send > 0) {

			rte_eth_tx_burst(gDpdkPortId, 0, tx, nb_send);

			unsigned i = 0;
			for(i = 0; i < nb_send; i++) {

				rte_pktmbuf_free(tx[i]);
			}
		}
#if ENABLE_TIMER

		static uint64_t prev_tsc = 0, cur_tsc;
		uint64_t diff_tsc;

		cur_tsc = rte_rdtsc();
		diff_tsc = cur_tsc - prev_tsc;
		if (diff_tsc > TIMER_RESOLUTION_CYCLES) {
			rte_timer_manage();
			prev_tsc = cur_tsc;
		}

#endif


	}

}

本文来自互联网用户投稿，该文观点仅代表作者本人，不代表本站立场。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如若转载，请注明出处：/a/731725.html

如若内容造成侵权/违法违规/事实不符，请联系我们进行投诉反馈qq邮箱809451989@qq.com，一经查实，立即删除！

相关文章

【Redis】List的常用命令以及常用场景

【Redis】List的常用命令以及常用场景

Redis List 是一个简单的链表&#xff0c;支持在两端进行插入和删除操作。这种数据结构在许多场景下非常有用&#xff0c;例如任务队列、消息队列等。Redis 提供了一系列针对 List 的操作命令&#xff0c;帮助我们更高效地操作链表。 1. List常用命令 操作类型命令时间复杂度…
阅读更多...
Redis-使用 jedis 操作数据

Redis-使用 jedis 操作数据

文章目录 1、Jedis简介2、环境准备3、创建maven普通项目,导入如下依赖4、测试JAVA程序和Redis之间的通信 1、Jedis简介 "Jedis" 通常是作为 "Java Redis" 的缩写或简称来理解的。Java Embedded Data Structures Interface 表示 Java嵌入式数据结构接口 2、…
阅读更多...
如何生成protobuf文件

如何生成protobuf文件

背景 protobuf是一种用于序列化结构数据的工具&#xff0c;实现数据的存储与交换&#xff0c;与编程语言和开发平台无关。 序列化&#xff1a;将结构数据或者对象转换成能够用于存储和传输的格式。 反序列化&#xff1a;在其他的计算环境中&#xff0c;将序列化后的数据还原为…
阅读更多...
解决双击bootstrap.bat没有生成b2.exe文件

解决双击bootstrap.bat没有生成b2.exe文件

双击bootstrap.bat但是并没有没有生成b2.exe文件&#xff0c;会报如下错误&#xff1a; "cl" 不是内部或外部命令&#xff0c;也不是可运行的程序 或批处理文件。D:\cppsoft\boost_1_85_0\tools\build\src\engine>dir *.exe 驱动器 D 中的卷是 Data 卷的序列号是…
阅读更多...
Swoole_loader扩展安装图文教程 Swoole扩展文件下载

Swoole_loader扩展安装图文教程 Swoole扩展文件下载

Swoole_loader扩展安装图文教程 Swoole扩展文件下载 安装和配置Swoole Loader 1 - 下载Swoole Loader 请下载兼容PHP7.2和非线程安全的Swoole Loader扩展&#xff0c;点击下载适配环境的扩展文件 2 - 安装Swoole Loader 将刚才下载的Swoole Loader扩展文件&#xff08;swo…
阅读更多...
AI播客下载：Machine Learning Street Talk（AI机器学习）

AI播客下载：Machine Learning Street Talk（AI机器学习）

该频道由 Tim Scarfe 博士、Yannic Kilcher 博士和 Keith Duggar 博士管理。 他们做了出色的工作&#xff0c;对每个节目进行了彻底的研究&#xff0c;并与机器学习行业中一些受过最高教育、最全面的嘉宾进行了双向对话。 每一集都会教授一些新内容&#xff0c;并且提供未经过滤…
阅读更多...
【从零到一】电子元器件网站建设/开发方案、流程及搭建要点全解

【从零到一】电子元器件网站建设/开发方案、流程及搭建要点全解

电子元器件行业在数字化转型的大潮下也迎来了前所未有的发展机遇。一个高效、专业、用户友好的电子元器件网站&#xff0c;不仅能够提升品牌形象&#xff0c;还能显著提高销售转化率&#xff0c;增强客户粘性。道合顺芯站点将详细阐述电子元器件开发方案、实施流程&#xff0c;…
阅读更多...
STM32通过SPI硬件读写W25Q64

STM32通过SPI硬件读写W25Q64

文章目录 1. W25Q64 2. 硬件电路 3. 软件/硬件波形对比 4. STM32中的SPI外设 5. 代码实现 5.1 MyI2C.c 5.2 MyI2C.h 5.3 W25Q64.c 5.4 W25Q64.h 5.5 W25Q64_Ins.h 5.6 main.c 1. W25Q64 对于SPI通信和W25Q64的详细解析可以看下面这篇文章 STM32单片机SPI通信详解-C…
阅读更多...
C语言 | Leetcode C语言题解之第172题阶乘后的零

C语言 | Leetcode C语言题解之第172题阶乘后的零

题目&#xff1a; 题解&#xff1a; int trailingZeroes(int n) {int ans 0;while (n) {n / 5;ans n;}return ans; }
阅读更多...
南昌代理记账报税的详细说明

南昌代理记账报税的详细说明

随着社会经济的发展和企业运营的需要&#xff0c;越来越多的企业开始寻找专业的会计服务&#xff0c;我们特别为您提供南昌代理记账报税的相关信息。 https://www.9733.cn/news/detail/166.html 代理记账的主要功能 1、代理记账为企业提供专业化的财务咨询服务。 2、及时准确…
阅读更多...
【Linux系统】Linux 命令行查看当前目录的总大小/总磁盘空间

【Linux系统】Linux 命令行查看当前目录的总大小/总磁盘空间

&#x1f601;博客主页&#x1f601;&#xff1a;&#x1f680;https://blog.csdn.net/wkd_007&#x1f680; &#x1f911;博客内容&#x1f911;&#xff1a;&#x1f36d;嵌入式开发、Linux、C语言、C、数据结构、音视频&#x1f36d; ⏰发布时间⏰&#xff1a;2024-06-22 0…
阅读更多...
ECharts 蓝色系-荧光图标折线图01案例

ECharts 蓝色系-荧光图标折线图01案例

ECharts 蓝色系-荧光图标折线图01案例 图表意义 本折线图案例展示了一周内不同路线的使用情况或数据统计。通过折线的上升和下降&#xff0c;可以直观地观察到每条路线的流量或数据变化趋势&#xff0c;从而进行分析和决策。 效果预览 效果图展示不同路线的数据统计和个性化…
阅读更多...
DVWA 靶场 Authorisation Bypass 通关解析

DVWA 靶场 Authorisation Bypass 通关解析

前言 DVWA代表Damn Vulnerable Web Application&#xff0c;是一个用于学习和练习Web应用程序漏洞的开源漏洞应用程序。它被设计成一个易于安装和配置的漏洞应用程序&#xff0c;旨在帮助安全专业人员和爱好者了解和熟悉不同类型的Web应用程序漏洞。 DVWA提供了一系列的漏洞场…
阅读更多...
Java宝藏实验资源库（8）多态、抽象类和接口

Java宝藏实验资源库（8）多态、抽象类和接口

一、实验目的 理解面向对象程序的基本概念。掌握类的继承和多态的实现机制。熟悉抽象类和接口的用法。 二、实验内容、过程及结果 **1.Using the classes defined in Listing 13.1, 13.2, 13.3, write a test program that creates an array of some Circle and Rectangle in…
阅读更多...
docker换源

docker换源

文章目录 前言1. 查找可用的镜像源2. 配置 Docker 镜像源3. 重启 Docker 服务4. 查看dock info是否修改成功5. 验证镜像源是否更换成功注意事项 前言 在pull镜像时遇到如下报错&#xff1a; ┌──(root㉿kali)-[/home/longl] └─# docker pull hello-world Using default …
阅读更多...
IPv6 address status lifetime

IPv6 address status lifetime

IPv6 地址状态转换 Address lifetime (地址生存期) 每个配置的 IPv6 单播地址都有一个生存期设置&#xff0c;该设置确定该地址在必须刷新或替换之前可以使用多长时间。某些地址设置为“永久”并且不会过期。“首选”和“有效”生存期用于指定其使用期限和可用性。 自动配置的…
阅读更多...
基于WPF技术的换热站智能监控系统16--动态数据绑定

基于WPF技术的换热站智能监控系统16--动态数据绑定

1、实现思路 1&#xff09;实时读取到的数据绑定到前台UI控件上&#xff0c;这个通过MVVM模式实现&#xff0c;同时注意实时读取必须通过任务task异步方式&#xff0c;这就需要读取PLC数据。 2&#xff09;UI控件的动作&#xff0c;如开或关水泵&#xff0c;必定能够将值写入…
阅读更多...
常见的Wi-Fi蓝牙模组

常见的Wi-Fi蓝牙模组

在嵌入式领域&#xff0c;常见的Wi-Fi蓝牙模组确实包括多个知名品牌&#xff0c;如乐鑫、安信可和移远等&#xff0c;以前可能你听的最多的是ESP8266&#xff0c;不过今天讨论的是Wi-Fi蓝牙模组&#xff0c;而8266本身并不内置蓝牙功能&#xff0c;不在介绍范围。而拿到模块之后…
阅读更多...
graalvm jdk和openjdk

graalvm jdk和openjdk

下载地址:https://github.com/graalvm/graalvm-ce-builds/releases 官网: https://www.graalvm.org
阅读更多...
设计模式4-模版方法

设计模式4-模版方法

设计模式 重构获得模式重构的关键技法1. 静态转动态2. 早绑定转晚绑定3. 继承转组合4. 编译时依赖转运行时依赖5. 紧耦合转松耦合 组件协助动机模式定义结构 要点总结。 例子示例解释&#xff1a; 重构获得模式 设计模式的目的是应对变化&#xff0c;提高复用 设计模式的要点…
阅读更多...
最新文章

Copyright @ 2022~2023