+++ /dev/null
-/*
- * Uses a two-level B-tree to store a set of key-value pairs.
- *
- * September 2, 2012
- * Eleanor Cawthon
- * eleanor.cawthon@inktank.com
- *
- * This is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License version 2.1, as published by the Free Software
- * Foundation. See file COPYING.
- */
-
-#ifndef KVFLATBTREEASYNC_H_
-#define KVFLATBTREEASYNC_H_
-
-#define ESUICIDE 134
-#define EPREFIX 136
-#define EFIRSTOBJ 138
-
-#include "key_value_store/key_value_structure.h"
-#include "include/utime.h"
-#include "include/types.h"
-#include "include/encoding.h"
-#include "common/Mutex.h"
-#include "common/Clock.h"
-#include "common/Formatter.h"
-#include "global/global_context.h"
-#include "include/rados/librados.hpp"
-#include <cfloat>
-#include <queue>
-#include <sstream>
-#include <stdarg.h>
-
-using namespace std;
-using ceph::bufferlist;
-
-enum {
- ADD_PREFIX = 1,
- MAKE_OBJECT = 2,
- UNWRITE_OBJECT = 3,
- RESTORE_OBJECT = 4,
- REMOVE_OBJECT = 5,
- REMOVE_PREFIX = 6,
- AIO_MAKE_OBJECT = 7
-};
-
-struct rebalance_args;
-
-
-/**
- * stores information about a key in the index.
- *
- * prefix is "0" unless key is "", in which case it is "1". This ensures that
- * the object with key "" will always be the highest key in the index.
- */
-struct key_data {
- string raw_key;
- string prefix;
-
- key_data()
- {}
-
- /**
- * @pre: key is a raw key (does not contain a prefix)
- */
- key_data(string key)
- : raw_key(key)
- {
- raw_key == "" ? prefix = "1" : prefix = "0";
- }
-
- bool operator==(key_data k) const {
- return ((raw_key == k.raw_key) && (prefix == k.prefix));
- }
-
- bool operator!=(key_data k) const {
- return ((raw_key != k.raw_key) || (prefix != k.prefix));
- }
-
- bool operator<(key_data k) const {
- return this->encoded() < k.encoded();
- }
-
- bool operator>(key_data k) const {
- return this->encoded() > k.encoded();
- }
-
- /**
- * parses the prefix from encoded and stores the data in this.
- *
- * @pre: encoded has a prefix
- */
- void parse(string encoded) {
- prefix = encoded[0];
- raw_key = encoded.substr(1,encoded.length());
- }
-
- /**
- * returns a string containing the encoded (prefixed) key
- */
- string encoded() const {
- return prefix + raw_key;
- }
-
- void encode(bufferlist &bl) const {
- ENCODE_START(1,1,bl);
- ::encode(raw_key, bl);
- ::encode(prefix, bl);
- ENCODE_FINISH(bl);
- }
- void decode(bufferlist::iterator &p) {
- DECODE_START(1, p);
- ::decode(raw_key, p);
- ::decode(prefix, p);
- DECODE_FINISH(p);
- }
-};
-WRITE_CLASS_ENCODER(key_data)
-
-
-/**
- * Stores information read from a librados object.
- */
-struct object_data {
- key_data min_kdata; //the max key from the previous index entry
- key_data max_kdata; //the max key, from the index
- string name; //the object's name
- map<std::string, bufferlist> omap; // the omap of the object
- bool unwritable; // an xattr that, if false, means an op is in
- // progress and other clients should not write to it.
- uint64_t version; //the version at time of read
- uint64_t size; //the number of elements in the omap
-
- object_data()
- : unwritable(false),
- version(0),
- size(0)
- {}
-
- object_data(string the_name)
- : name(the_name),
- unwritable(false),
- version(0),
- size(0)
- {}
-
- object_data(key_data min, key_data kdat, string the_name)
- : min_kdata(min),
- max_kdata(kdat),
- name(the_name),
- unwritable(false),
- version(0),
- size(0)
- {}
-
- object_data(key_data min, key_data kdat, string the_name,
- map<std::string, bufferlist> the_omap)
- : min_kdata(min),
- max_kdata(kdat),
- name(the_name),
- omap(the_omap),
- unwritable(false),
- version(0),
- size(0)
- {}
-
- object_data(key_data min, key_data kdat, string the_name, int the_version)
- : min_kdata(min),
- max_kdata(kdat),
- name(the_name),
- unwritable(false),
- version(the_version),
- size(0)
- {}
-
- void encode(bufferlist &bl) const {
- ENCODE_START(1,1,bl);
- ::encode(min_kdata, bl);
- ::encode(max_kdata, bl);
- ::encode(name, bl);
- ::encode(omap, bl);
- ::encode(unwritable, bl);
- ::encode(version, bl);
- ::encode(size, bl);
- ENCODE_FINISH(bl);
- }
- void decode(bufferlist::iterator &p) {
- DECODE_START(1, p);
- ::decode(min_kdata, p);
- ::decode(max_kdata, p);
- ::decode(name, p);
- ::decode(omap, p);
- ::decode(unwritable, p);
- ::decode(version, p);
- ::decode(size, p);
- DECODE_FINISH(p);
- }
-};
-WRITE_CLASS_ENCODER(object_data)
-
-/**
- * information about objects to be created by a split or merge - stored in the
- * index_data.
- */
-struct create_data {
- key_data min;
- key_data max;
- string obj;
-
- create_data()
- {}
-
- create_data(key_data n, key_data x, string o)
- : min(n),
- max(x),
- obj(o)
- {}
-
- create_data(object_data o)
- : min(o.min_kdata),
- max(o.max_kdata),
- obj(o.name)
- {}
-
- create_data & operator=(const create_data &c) {
- min = c.min;
- max = c.max;
- obj = c.obj;
- return *this;
- }
-
- void encode(bufferlist &bl) const {
- ENCODE_START(1,1,bl);
- ::encode(min, bl);
- ::encode(max, bl);
- ::encode(obj, bl);
- ENCODE_FINISH(bl);
- }
- void decode(bufferlist::iterator &p) {
- DECODE_START(1, p);
- ::decode(min, p);
- ::decode(max, p);
- ::decode(obj, p);
- DECODE_FINISH(p);
- }
-};
-WRITE_CLASS_ENCODER(create_data)
-
-/**
- * information about objects to be deleted by a split or merge - stored in the
- * index_data.
- */
-struct delete_data {
- key_data min;
- key_data max;
- string obj;
- uint64_t version;
-
- delete_data()
- : version(0)
- {}
-
- delete_data(key_data n, key_data x, string o, uint64_t v)
- : min(n),
- max(x),
- obj(o),
- version(v)
- {}
-
- delete_data & operator=(const delete_data &d) {
- min = d.min;
- max = d.max;
- obj = d.obj;
- version = d.version;
- return *this;
- }
-
-
- void encode(bufferlist &bl) const {
- ENCODE_START(1,1,bl);
- ::encode(min, bl);
- ::encode(max, bl);
- ::encode(obj, bl);
- ::encode(version, bl);
- ENCODE_FINISH(bl);
- }
- void decode(bufferlist::iterator &p) {
- DECODE_START(1, p);
- ::decode(min, p);
- ::decode(max, p);
- ::decode(obj, p);
- ::decode(version, p);
- DECODE_FINISH(p);
- }
-};
-WRITE_CLASS_ENCODER(delete_data)
-
-/**
- * The index object is a key value map that stores
- * the highest key stored in an object as keys, and an index_data
- * as the corresponding value. The index_data contains the encoded
- * high and low keys (where keys in this object are > min_kdata and
- * <= kdata), the name of the librados object where keys containing
- * that range of keys are located, and information about split and
- * merge operations that may need to be cleaned up if a client dies.
- */
-struct index_data {
- //the encoded key corresponding to the object
- key_data kdata;
-
- //"1" if there is a prefix (because a split or merge is
- //in progress), otherwise ""
- string prefix;
-
- //the kdata of the previous index entry
- key_data min_kdata;
-
- utime_t ts; //time that a split/merge started
-
- //objects to be created
- vector<create_data > to_create;
-
- //objects to be deleted
- vector<delete_data > to_delete;
-
- //the name of the object where the key range is located.
- string obj;
-
- index_data()
- {}
-
- index_data(string raw_key)
- : kdata(raw_key)
- {}
-
- index_data(key_data max, key_data min, string o)
- : kdata(max),
- min_kdata(min),
- obj(o)
- {}
-
- index_data(create_data c)
- : kdata(c.max),
- min_kdata(c.min),
- obj(c.obj)
- {}
-
- bool operator<(const index_data &other) const {
- return (kdata.encoded() < other.kdata.encoded());
- }
-
- //true if there is a prefix and now - ts > timeout.
- bool is_timed_out(utime_t now, utime_t timeout) const;
-
- void encode(bufferlist &bl) const {
- ENCODE_START(1,1,bl);
- ::encode(prefix, bl);
- ::encode(min_kdata, bl);
- ::encode(kdata, bl);
- ::encode(ts, bl);
- ::encode(to_create, bl);
- ::encode(to_delete, bl);
- ::encode(obj, bl);
- ENCODE_FINISH(bl);
- }
- void decode(bufferlist::iterator &p) {
- DECODE_START(1, p);
- ::decode(prefix, p);
- ::decode(min_kdata, p);
- ::decode(kdata, p);
- ::decode(ts, p);
- ::decode(to_create, p);
- ::decode(to_delete, p);
- ::decode(obj, p);
- DECODE_FINISH(p);
- }
-
- /*
- * Prints a string representation of the information, in the following format:
- * (min_kdata/
- * kdata,
- * prefix
- * ts
- * elements of to_create, organized into (high key| obj name)
- * ;
- * elements of to_delete, organized into (high key| obj name | version number)
- * :
- * val)
- */
- string str() const {
- stringstream strm;
- strm << '(' << min_kdata.encoded() << "/" << kdata.encoded() << ','
- << prefix;
- if (prefix == "1") {
- strm << ts.sec() << '.' << ts.usec();
- for(vector<create_data>::const_iterator it = to_create.begin();
- it != to_create.end(); ++it) {
- strm << '(' << it->min.encoded() << '/' << it->max.encoded() << '|'
- << it->obj << ')';
- }
- strm << ';';
- for(vector<delete_data >::const_iterator it = to_delete.begin();
- it != to_delete.end(); ++it) {
- strm << '(' << it->min.encoded() << '/' << it->max.encoded() << '|'
- << it->obj << '|'
- << it->version << ')';
- }
- strm << ':';
- }
- strm << obj << ')';
- return strm.str();
- }
-};
-WRITE_CLASS_ENCODER(index_data)
-
-/**
- * Structure to store information read from the index for reuse.
- */
-class IndexCache {
-protected:
- map<key_data, pair<index_data, utime_t> > k2itmap;
- map<utime_t, key_data> t2kmap;
- int cache_size;
-
-public:
- IndexCache(int n)
- : cache_size(n)
- {}
- /**
- * Inserts idata into the cache and removes whatever key mapped to before.
- * If the cache is full, pops the oldest entry.
- */
- void push(const string &key, const index_data &idata);
-
- /**
- * Inserts idata into the cache. If idata.kdata is already in the cache,
- * replaces the old one. Pops the oldest entry if the cache is full.
- */
- void push(const index_data &idata);
-
- /**
- * Removes the oldest entry from the cache
- */
- void pop();
-
- /**
- * Removes the value associated with kdata from both maps
- */
- void erase(key_data kdata);
-
- /**
- * gets the idata where key belongs. If none, returns -ENODATA.
- */
- int get(const string &key, index_data *idata) const;
-
- /**
- * Gets the idata where key goes and the one after it. If there are not
- * valid entries for both of them, returns -ENODATA.
- */
- int get(const string &key, index_data *idata, index_data * next_idata) const;
- void clear();
-};
-
-class KvFlatBtreeAsync;
-
-
-/**
- * These are used internally to translate aio operations into useful thread
- * arguments.
- */
-struct aio_set_args {
- KvFlatBtreeAsync * kvba;
- string key;
- bufferlist val;
- bool exc;
- callback cb;
- void * cb_args;
- int * err;
-};
-
-struct aio_rm_args {
- KvFlatBtreeAsync * kvba;
- string key;
- callback cb;
- void * cb_args;
- int * err;
-};
-
-struct aio_get_args {
- KvFlatBtreeAsync * kvba;
- string key;
- bufferlist * val;
- bool exc;
- callback cb;
- void * cb_args;
- int * err;
-};
-
-class KvFlatBtreeAsync : public KeyValueStructure {
-protected:
-
- //don't change these once operations start being called - they are not
- //protected with mutexes!
- int k;
- string index_name;
- librados::IoCtx io_ctx;
- string rados_id;
- string client_name;
- librados::Rados rados;
- string pool_name;
- injection_t interrupt;
- int wait_ms;
- utime_t timeout; //declare a client dead if it goes this long without
- //finishing a split/merge
- int cache_size;
- double cache_refresh; //read cache_size / cache_refresh entries each time the
- //index is read
- bool verbose;//if true, display lots of debug output
-
- //shared variables protected with mutexes
- Mutex client_index_lock;
- int client_index; //names of new objects are client_name.client_index
- Mutex icache_lock;
- IndexCache icache;
- friend struct index_data;
-
- /**
- * finds the object in the index with the lowest key value that is greater
- * than idata.kdata. If idata.kdata is the max key, returns -EOVERFLOW. If
- * idata has a prefix and has timed out, cleans up.
- *
- * @param idata: idata for the object to search for.
- * @param out_data: the idata for the next object.
- *
- * @pre: idata must contain a key_data.
- * @post: out_data contains complete information
- */
- int next(const index_data &idata, index_data * out_data);
-
- /**
- * finds the object in the index with the lowest key value that is greater
- * than idata.kdata. If idata.kdata is the lowest key, returns -ERANGE If
- * idata has a prefix and has timed out, cleans up.
- *
- * @param idata: idata for the object to search for.
- * @param out_data: the idata for the next object.
- *
- * @pre: idata must contain a key_data.
- * @post: out_data contains complete information
- */
- int prev(const index_data &idata, index_data * out_data);
-
- /**
- * finds the index_data where a key belongs, from cache if possible. If it
- * reads the index object, it will read the first cache_size entries after
- * key and put them in the cache.
- *
- * @param key: the key to search for
- * @param idata: the index_data for the first index value such that idata.key
- * is greater than key.
- * @param next_idata: if not NULL, this will be set to the idata after idata
- * @param force_update: if false, will try to read from cache first.
- *
- * @pre: key is not encoded
- * @post: idata contains complete information
- * stored
- */
- int read_index(const string &key, index_data * idata,
- index_data * next_idata, bool force_update);
-
- /**
- * Reads obj and generates information about it. Iff the object has >= 2k
- * entries, reads the whole omap and then splits it.
- *
- * @param idata: index data for the object being split
- * @pre: idata contains a key and an obj
- * @post: idata.obj has been split and icache has been updated
- * @return -EBALANCE if obj does not need to be split, 0 if split successful,
- * error from read_object or perform_ops if there is one.
- */
- int split(const index_data &idata);
-
- /**
- * reads o1 and the next object after o1 and, if necessary, rebalances them.
- * if hk1 is the highest key in the index, calls rebalance on the next highest
- * key.
- *
- * @param idata: index data for the object being rebalanced
- * @param next_idata: index data for the next object. If blank, will read.
- * @pre: idata contains a key and an obj
- * @post: idata.obj has been rebalanced and icache has been updated
- * @return -EBALANCE if no change needed, -ENOENT if o1 does not exist,
- * -ECANCELED if second object does not exist, otherwise, error from
- * perform_ops
- */
- int rebalance(const index_data &idata1, const index_data &next_idata);
-
- /**
- * performs an ObjectReadOperation to populate odata
- *
- * @post: odata has all information about obj except for key (which is "")
- */
- int read_object(const string &obj, object_data * odata);
-
- /**
- * performs a maybe_read_for_balance ObjectOperation so the omap is only
- * read if the object is out of bounds.
- */
- int read_object(const string &obj, rebalance_args * args);
-
- /**
- * sets up owo to change the index in preparation for a split/merge.
- *
- * @param to_create: vector of object_data to be created.
- * @param to_delete: vector of object_data to be deleted.
- * @param owo: the ObjectWriteOperation to set up
- * @param idata: will be populated by index data for this op.
- * @param err: error code reference to pass to omap_cmp
- * @pre: entries in to_create and to_delete must have keys and names.
- */
- void set_up_prefix_index(
- const vector<object_data> &to_create,
- const vector<object_data> &to_delete,
- librados::ObjectWriteOperation * owo,
- index_data * idata,
- int * err);
-
- /**
- * sets up all make, mark, restore, and delete ops, as well as the remove
- * prefix op, based on idata.
- *
- * @param create_vector: vector of data about the objects to be created.
- * @pre: entries in create_data must have names and omaps and be in idata
- * order
- * @param delete_vector: vector of data about the objects to be deleted
- * @pre: entries in to_delete must have versions and be in idata order
- * @param ops: the owos to set up. the pair is a pair of op identifiers
- * and names of objects - set_up_ops fills these in.
- * @pre: ops must be the correct size and the ObjectWriteOperation pointers
- * must be valid.
- * @param idata: the idata with information about how to set up the ops
- * @pre: idata has valid to_create and to_delete
- * @param err: the int to get the error value for omap_cmp
- */
- void set_up_ops(
- const vector<object_data> &create_vector,
- const vector<object_data> &delete_vector,
- vector<pair<pair<int, string>, librados::ObjectWriteOperation*> > * ops,
- const index_data &idata,
- int * err);
-
- /**
- * sets up owo to exclusive create, set omap to to_set, and set
- * unwritable to "0"
- */
- void set_up_make_object(
- const map<std::string, bufferlist> &to_set,
- librados::ObjectWriteOperation *owo);
-
- /**
- * sets up owo to assert object version and that object version is
- * writable,
- * then mark it unwritable.
- *
- * @param ver: if this is 0, no version is asserted.
- */
- void set_up_unwrite_object(
- const int &ver, librados::ObjectWriteOperation *owo);
-
- /**
- * sets up owo to assert that an object is unwritable and then mark it
- * writable
- */
- void set_up_restore_object(
- librados::ObjectWriteOperation *owo);
-
- /**
- * sets up owo to assert that the object is unwritable and then remove it
- */
- void set_up_delete_object(
- librados::ObjectWriteOperation *owo);
-
- /**
- * perform the operations in ops and handles errors.
- *
- * @param debug_prefix: what to print at the beginning of debug output
- * @param idata: the idata for the object being operated on, to be
- * passed to cleanup if necessary
- * @param ops: this contains an int identifying the type of op,
- * a string that is the name of the object to operate on, and a pointer
- * to the ObjectWriteOperation to use. All of this must be complete.
- * @post: all operations are performed and most errors are handled
- * (e.g., cleans up if an assertion fails). If an unknown error is found,
- * returns it.
- */
- int perform_ops( const string &debug_prefix,
- const index_data &idata,
- vector<pair<pair<int, string>, librados::ObjectWriteOperation*> > * ops);
-
- /**
- * Called when a client discovers that another client has died during a
- * split or a merge. cleans up after that client.
- *
- * @param idata: the index data parsed from the index entry left by the dead
- * client.
- * @param error: the error that caused the client to realize the other client
- * died (should be -ENOENT or -ETIMEDOUT)
- * @post: rolls forward if -ENOENT, otherwise rolls back.
- */
- int cleanup(const index_data &idata, const int &error);
-
- /**
- * does the ObjectWriteOperation and splits, reads the index, and/or retries
- * until success.
- */
- int set_op(const string &key, const bufferlist &val,
- bool update_on_existing, index_data &idata);
-
- /**
- * does the ObjectWriteOperation and merges, reads the index, and/or retries
- * until success.
- */
- int remove_op(const string &key, index_data &idata, index_data &next_idata);
-
- /**
- * does the ObjectWriteOperation and reads the index and/or retries
- * until success.
- */
- int get_op(const string &key, bufferlist * val, index_data &idata);
-
- /**
- * does the ObjectWriteOperation and splits, reads the index, and/or retries
- * until success.
- */
- int handle_set_rm_errors(int &err, string key, string obj,
- index_data * idata, index_data * next_idata);
-
- /**
- * called by aio_set, aio_remove, and aio_get, respectively.
- */
- static void* pset(void *ptr);
- static void* prm(void *ptr);
- static void* pget(void *ptr);
-public:
-
-
- //interruption methods, for correctness testing
- /**
- * returns 0
- */
- int nothing() override;
- /**
- * 10% chance of waiting wait_ms seconds
- */
- int wait() override;
- /**
- * 10% chance of killing the client.
- */
- int suicide() override;
-
-KvFlatBtreeAsync(int k_val, string name, int cache, double cache_r,
- bool verb)
- : k(k_val),
- index_name("index_object"),
- rados_id(name),
- client_name(string(name).append(".")),
- pool_name("rbd"),
- interrupt(&KeyValueStructure::nothing),
- wait_ms(0),
- timeout(100000,0),
- cache_size(cache),
- cache_refresh(cache_r),
- verbose(verb),
- client_index_lock("client_index_lock"),
- client_index(0),
- icache_lock("icache_lock"),
- icache(cache)
- {}
-
- /**
- * creates a string with an int at the end.
- *
- * @param s: the string on the left
- * @param i: the int to be appended to the string
- * @return the string
- */
- static string to_string(string s, int i);
-
- /**
- * returns in encoded
- */
- static bufferlist to_bl(const string &in) {
- bufferlist bl;
- bl.append(in);
- return bl;
- }
-
- /**
- * returns idata encoded;
- */
- static bufferlist to_bl(const index_data &idata) {
- bufferlist bl;
- idata.encode(bl);
- return bl;
- }
-
- /**
- * returns the rados_id of this KvFlatBtreeAsync
- */
- string get_name();
-
- /**
- * sets this kvba to call inject before every ObjectWriteOperation.
- * If inject is wait and wait_time is set, wait will have a 10% chance of
- * sleeping for waite_time miliseconds.
- */
- void set_inject(injection_t inject, int wait_time) override;
-
- /**
- * sets up the rados and io_ctx of this KvFlatBtreeAsync. If the don't already
- * exist, creates the index and max object.
- */
- int setup(int argc, const char** argv) override;
-
- int set(const string &key, const bufferlist &val,
- bool update_on_existing) override;
-
- int remove(const string &key) override;
-
- /**
- * returns true if all of the following are true:
- *
- * all objects are accounted for in the index or a prefix
- * (i.e., no floating objects)
- * all objects have k <= size <= 2k
- * all keys in an object are within the specified predicted by the index
- *
- * if any of those fails, states that the problem(s) are, and prints str().
- *
- * @pre: no operations are in progress
- */
- bool is_consistent() override;
-
- /**
- * returns an ASCII representation of the index and sub objects, showing
- * stats about each object and all omaps. Don't use if you have more than
- * about 10 objects.
- */
- string str() override;
-
- int get(const string &key, bufferlist *val) override;
-
- //async versions of these methods
- void aio_get(const string &key, bufferlist *val, callback cb,
- void *cb_args, int * err) override;
- void aio_set(const string &key, const bufferlist &val, bool exclusive,
- callback cb, void * cb_args, int * err) override;
- void aio_remove(const string &key, callback cb, void *cb_args, int * err) override;
-
- //these methods that deal with multiple keys at once are efficient, but make
- //no guarantees about atomicity!
-
- /**
- * Removes all objects and resets the store as if setup had just run. Makes no
- * attempt to do this safely - make sure this is the only operation running
- * when it is called!
- */
- int remove_all() override;
-
- /**
- * This does not add prefixes to the index and therefore DOES NOT guarantee
- * consistency! It is ONLY safe if there is only one instance at a time.
- * It follows the same general logic as a rebalance, but
- * with all objects that contain any of the keys in in_map. It is O(n), where
- * n is the number of librados objects it has to change. Higher object sizes
- * (i.e., k values) also decrease the efficiency of this method because it
- * copies all of the entries in each object it modifies. Writing new objects
- * is done in parallel.
- *
- * This is efficient if:
- * * other clients are very unlikely to be modifying any of the objects while
- * this operation is in progress
- * * The entries in in_map are close together
- * * It is especially efficient for initially entering lots of entries into
- * an empty structure.
- *
- * It is very inefficient compared to setting one key and/or will starve if:
- * * other clients are modifying the objects it tries to modify
- * * The keys are distributed across the range of keys in the store
- * * there is a small number of keys compared to k
- */
- int set_many(const map<string, bufferlist> &in_map) override;
-
- int get_all_keys(std::set<string> *keys) override;
- int get_all_keys_and_values(map<string,bufferlist> *kv_map) override;
-
-};
-
-#endif /* KVFLATBTREEASYNC_H_ */
Code Review / stor4nfv.git / blobdiff