(Probably almost) implement cluster client

cluster_client.h

@@ -0,0 +1,74 @@
+#pragma once
+
+#include "messenger.h"
+#include "etcd_state_client.h"
+
+#define MIN_BLOCK_SIZE 4*1024
+#define MAX_BLOCK_SIZE 128*1024*1024
+#define DEFAULT_BLOCK_SIZE 128*1024
+#define DEFAULT_PG_STRIPE_SIZE 4*1024*1024
+#define DEFAULT_DISK_ALIGNMENT 4096
+#define DEFAULT_BITMAP_GRANULARITY 4096
+
+struct cluster_op_t;
+
+struct cluster_op_part_t
+{
+    cluster_op_t *parent;
+    uint64_t offset;
+    uint32_t len;
+    pg_num_t pg_num;
+    osd_num_t osd_num;
+    void *buf;
+    bool sent;
+    bool done;
+    osd_op_t op;
+};
+
+struct cluster_op_t
+{
+    uint64_t opcode; // OSD_OP_READ, OSD_OP_WRITE
+    uint64_t inode;
+    uint64_t offset;
+    uint64_t len;
+    int retval;
+    void *buf;
+    std::function<void(cluster_op_t*)> callback;
+protected:
+    bool needs_reslice = false;
+    int sent_count = 0, done_count = 0;
+    std::vector<cluster_op_part_t> parts;
+    friend class cluster_client_t;
+};
+
+class cluster_client_t
+{
+    timerfd_manager_t *tfd;
+    ring_loop_t *ringloop;
+
+    uint64_t pg_part_count = 2;
+    uint64_t pg_stripe_size = 0;
+    uint64_t bs_block_size = 0;
+    uint64_t bs_disk_alignment = 0;
+    uint64_t bs_bitmap_granularity = 0;
+    uint64_t pg_count = 0;
+    int log_level;
+
+    uint64_t op_id = 1;
+    etcd_state_client_t st_cli;
+    osd_messenger_t msgr;
+    std::set<cluster_op_t*> sent_ops, unsent_ops;
+
+public:
+    cluster_client_t(ring_loop_t *ringloop, timerfd_manager_t *tfd);
+    void execute(cluster_op_t *op);
+
+protected:
+    void continue_ops();
+    void on_load_config_hook(json11::Json::object & cfg);
+    void on_load_pgs_hook(bool success);
+    void on_change_hook(json11::Json::object & changes);
+    void on_change_osd_state_hook(uint64_t peer_osd);
+    bool try_send(cluster_op_t *op, cluster_op_part_t *part);
+    void handle_op_part(cluster_op_part_t *part);
+};