Completed the implementation and test cases for Redis API.

Summary:
Completed the implementation for the Redis API for Lists.
The Redis API uses rocksdb as a backend to persistently
store maps from key->list. It supports basic operations
for appending, inserting, pushing, popping, and accessing
a list, given its key.

Test Plan:
  - Compile with: make redis_test
  - Test with: ./redis_test
  - Run all unit tests (for all rocksdb) with: make all check
  - To use an interactive REDIS client use: ./redis_test -m
  - To clean the database before use:       ./redis_test -m -d

Reviewers: haobo, dhruba, zshao

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10833
This commit is contained in:
Deon Nicholas 2013-06-11 11:19:49 -07:00
parent e673d5d26d
commit 5679107b07
8 changed files with 1905 additions and 2 deletions

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@ -62,7 +62,8 @@ TESTS = \
auto_roll_logger_test \
filelock_test \
merge_test \
stringappend_test
stringappend_test \
redis_test
TOOLS = \
sst_dump \
@ -183,6 +184,9 @@ coding_test: util/coding_test.o $(LIBOBJECTS) $(TESTHARNESS)
stringappend_test: utilities/merge_operators/string_append/stringappend_test.o $(LIBOBJECTS) $(TESTHARNESS)
$(CXX) utilities/merge_operators/string_append/stringappend_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS)
redis_test: utilities/redis/redis_lists_test.o $(LIBOBJECTS) $(TESTHARNESS)
$(CXX) utilities/redis/redis_lists_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS)
histogram_test: util/histogram_test.o $(LIBOBJECTS) $(TESTHARNESS)
$(CXX) util/histogram_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o$@ $(LDFLAGS)

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@ -8,10 +8,10 @@
#include <memory>
#include <assert.h>
#include "leveldb/slice.h"
#include "leveldb/merge_operator.h"
#include "utilities/merge_operators.h"
#include <iostream>
namespace leveldb {

14
utilities/redis/README Normal file
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@ -0,0 +1,14 @@
This folder defines a REDIS-style interface for Rocksdb.
Right now it is written as a simple tag-on in the leveldb::RedisLists class.
It implements Redis Lists, and supports only the "non-blocking operations".
Internally, the set of lists are stored in a rocksdb database, mapping keys to
values. Each "value" is the list itself, storing a sequence of "elements".
Each element is stored as a 32-bit-integer, followed by a sequence of bytes.
The 32-bit-integer represents the length of the element (that is, the number
of bytes that follow). And then that many bytes follow.
NOTE: This README file may be old. See the actual redis_lists.cc file for
definitive details on the implementation. There should be a header at the top
of that file, explaining a bit of the implementation details.

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@ -0,0 +1,24 @@
/**
* A simple structure for exceptions in RedisLists.
*
* @author Deon Nicholas (dnicholas@fb.com)
* Copyright 2013 Facebook
*/
#ifndef LEVELDB_REDIS_LIST_EXCEPTION_H
#define LEVELDB_REDIS_LIST_EXCEPTION_H
#include <exception>
namespace leveldb {
class RedisListException: public std::exception {
public:
const char* what() const throw() {
return "Invalid operation or corrupt data in Redis List.";
}
};
} // namespace leveldb
#endif // LEVELDB_REDIS_LIST_EXCEPTION_H

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@ -0,0 +1,306 @@
/**
* RedisListIterator:
* An abstraction over the "list" concept (e.g.: for redis lists).
* Provides functionality to read, traverse, edit, and write these lists.
*
* Upon construction, the RedisListIterator is given a block of list data.
* Internally, it stores a pointer to the data and a pointer to current item.
* It also stores a "result" list that will be mutated over time.
*
* Traversal and mutation are done by "forward iteration".
* The Push() and Skip() methods will advance the iterator to the next item.
* However, Push() will also "write the current item to the result".
* Skip() will simply move to next item, causing current item to be dropped.
*
* Upon completion, the result (accessible by WriteResult()) will be saved.
* All "skipped" items will be gone; all "pushed" items will remain.
*
* @throws Any of the operations may throw a RedisListException if an invalid
* operation is performed or if the data is found to be corrupt.
*
* @notes By default, if WriteResult() is called part-way through iteration,
* it will automatically advance the iterator to the end, and Keep()
* all items that haven't been traversed yet. This may be subject
* to review.
*
* @notes Can access the "current" item via GetCurrent(), and other
* list-specific information such as Length().
*
* @notes The internal representation is due to change at any time. Presently,
* the list is represented as follows:
* - 32-bit integer header: the number of items in the list
* - For each item:
* - 32-bit int (n): the number of bytes representing this item
* - n bytes of data: the actual data.
*
* @author Deon Nicholas (dnicholas@fb.com)
* Copyright 2013 Facebook
*/
#include <string>
#include "redis_list_exception.h"
#include "leveldb/slice.h"
#include "util/coding.h"
namespace leveldb {
/// An abstraction over the "list" concept.
/// All operations may throw a RedisListException
class RedisListIterator {
public:
/// Construct a redis-list-iterator based on data.
/// If the data is non-empty, it must formatted according to @notes above.
///
/// If the data is valid, we can assume the following invariant(s):
/// a) length_, num_bytes_ are set correctly.
/// b) cur_byte_ always refers to the start of the current element,
/// just before the bytes that specify element length.
/// c) cur_elem_ is always the index of the current element.
/// d) cur_elem_length_ is always the number of bytes in current element,
/// excluding the 4-byte header itself.
/// e) result_ will always contain data_[0..cur_byte_) and a header
/// f) Whenever corrupt data is encountered or an invalid operation is
/// attempted, a RedisListException will immediately be thrown.
RedisListIterator(const std::string& list_data)
: data_(list_data.data()),
num_bytes_(list_data.size()),
cur_byte_(0),
cur_elem_(0),
cur_elem_length_(0),
length_(0),
result_() {
// Initialize the result_ (reserve enough space for header)
InitializeResult();
// Parse the data only if it is not empty.
if (num_bytes_ == 0) {
return;
}
// If non-empty, but less than 4 bytes, data must be corrupt
if (num_bytes_ < sizeof(length_)) {
ThrowError("Corrupt header."); // Will break control flow
}
// Good. The first bytes specify the number of elements
length_ = DecodeFixed32(data_);
cur_byte_ = sizeof(length_);
// If we have at least one element, point to that element.
// Also, read the first integer of the element (specifying the size),
// if possible.
if (length_ > 0) {
if (cur_byte_ + sizeof(cur_elem_length_) <= num_bytes_) {
cur_elem_length_ = DecodeFixed32(data_+cur_byte_);
} else {
ThrowError("Corrupt data for first element.");
}
}
// At this point, we are fully set-up.
// The invariants described in the header should now be true.
}
/// Reserve some space for the result_.
/// Equivalent to result_.reserve(bytes).
void Reserve(int bytes) {
result_.reserve(bytes);
}
/// Go to next element in data file.
/// Also writes the current element to result_.
RedisListIterator& Push() {
WriteCurrentElement();
MoveNext();
return *this;
}
/// Go to next element in data file.
/// Drops/skips the current element. It will not be written to result_.
RedisListIterator& Skip() {
MoveNext();
--length_; // One less item
--cur_elem_; // We moved one forward, but index did not change
return *this;
}
/// Insert elem into the result_ (just BEFORE the current element / byte)
/// Note: if Done() (i.e.: iterator points to end), this will append elem.
void InsertElement(const Slice& elem) {
// Ensure we are in a valid state
CheckErrors();
const int kOrigSize = result_.size();
result_.resize(kOrigSize + SizeOf(elem));
EncodeFixed32(result_.data() + kOrigSize, elem.size());
memcpy(result_.data() + kOrigSize + sizeof(uint32_t),
elem.data(),
elem.size());
++length_;
++cur_elem_;
}
/// Access the current element, and save the result into *curElem
void GetCurrent(Slice* curElem) {
// Ensure we are in a valid state
CheckErrors();
// Ensure that we are not past the last element.
if (Done()) {
ThrowError("Invalid dereferencing.");
}
// Dereference the element
*curElem = Slice(data_+cur_byte_+sizeof(cur_elem_length_),
cur_elem_length_);
}
// Number of elements
int Length() const {
return length_;
}
// Number of bytes in the final representation (i.e: WriteResult().size())
int Size() const {
// result_ holds the currently written data
// data_[cur_byte..num_bytes-1] is the remainder of the data
return result_.size() + (num_bytes_ - cur_byte_);
}
// Reached the end?
bool Done() const {
return cur_byte_ >= num_bytes_ || cur_elem_ >= length_;
}
/// Returns a string representing the final, edited, data.
/// Assumes that all bytes of data_ in the range [0,cur_byte_) have been read
/// and that result_ contains this data.
/// The rest of the data must still be written.
/// So, this method ADVANCES THE ITERATOR TO THE END before writing.
Slice WriteResult() {
CheckErrors();
// The header should currently be filled with dummy data (0's)
// Correctly update the header.
// Note, this is safe since result_ is a vector (guaranteed contiguous)
EncodeFixed32(&result_[0],length_);
// Append the remainder of the data to the result.
result_.insert(result_.end(),data_+cur_byte_, data_ +num_bytes_);
// Seek to end of file
cur_byte_ = num_bytes_;
cur_elem_ = length_;
cur_elem_length_ = 0;
// Return the result
return Slice(result_.data(),result_.size());
}
public: // Static public functions
/// An upper-bound on the amount of bytes needed to store this element.
/// This is used to hide representation information from the client.
/// E.G. This can be used to compute the bytes we want to Reserve().
static uint32_t SizeOf(const Slice& elem) {
// [Integer Length . Data]
return sizeof(uint32_t) + elem.size();
}
private: // Private functions
/// Initializes the result_ string.
/// It will fill the first few bytes with 0's so that there is
/// enough space for header information when we need to write later.
/// Currently, "header information" means: the length (number of elements)
/// Assumes that result_ is empty to begin with
void InitializeResult() {
assert(result_.empty()); // Should always be true.
result_.resize(sizeof(uint32_t),0); // Put a block of 0's as the header
}
/// Go to the next element (used in Push() and Skip())
void MoveNext() {
CheckErrors();
// Check to make sure we are not already in a finished state
if (Done()) {
ThrowError("Attempting to iterate past end of list.");
}
// Move forward one element.
cur_byte_ += sizeof(cur_elem_length_) + cur_elem_length_;
++cur_elem_;
// If we are at the end, finish
if (Done()) {
cur_elem_length_ = 0;
return;
}
// Otherwise, we should be able to read the new element's length
if (cur_byte_ + sizeof(cur_elem_length_) > num_bytes_) {
ThrowError("Corrupt element data.");
}
// Set the new element's length
cur_elem_length_ = DecodeFixed32(data_+cur_byte_);
return;
}
/// Append the current element (pointed to by cur_byte_) to result_
/// Assumes result_ has already been reserved appropriately.
void WriteCurrentElement() {
// First verify that the iterator is still valid.
CheckErrors();
if (Done()) {
ThrowError("Attempting to write invalid element.");
}
// Append the cur element.
result_.insert(result_.end(),
data_+cur_byte_,
data_+cur_byte_+ sizeof(uint32_t) + cur_elem_length_);
}
/// Will ThrowError() if neccessary.
/// Checks for common/ubiquitous errors that can arise after most operations.
/// This method should be called before any reading operation.
/// If this function succeeds, then we are guaranteed to be in a valid state.
/// Other member functions should check for errors and ThrowError() also
/// if an error occurs that is specific to it even while in a valid state.
void CheckErrors() {
// Check if any crazy thing has happened recently
if ((cur_elem_ > length_) || // Bad index
(cur_byte_ > num_bytes_) || // No more bytes
(cur_byte_ + cur_elem_length_ > num_bytes_) || // Item too large
(cur_byte_ == num_bytes_ && cur_elem_ != length_) || // Too many items
(cur_elem_ == length_ && cur_byte_ != num_bytes_)) { // Too many bytes
ThrowError("Corrupt data.");
}
}
/// Will throw an exception based on the passed-in message.
/// This function is guaranteed to STOP THE CONTROL-FLOW.
/// (i.e.: you do not have to call "return" after calling ThrowError)
void ThrowError(const char* const msg = NULL) {
// TODO: For now we ignore the msg parameter. This can be expanded later.
throw RedisListException();
}
private:
const char* const data_; // A pointer to the data (the first byte)
const uint32_t num_bytes_; // The number of bytes in this list
uint32_t cur_byte_; // The current byte being read
uint32_t cur_elem_; // The current element being read
uint32_t cur_elem_length_; // The number of bytes in current element
uint32_t length_; // The number of elements in this list
std::vector<char> result_; // The output data
};
} // namespace leveldb

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@ -0,0 +1,551 @@
/**
* A (persistent) Redis API built using the rocksdb backend.
* Implements Redis Lists as described on: http://redis.io/commands#list
*
* @throws All functions may throw a RedisListException on error/corruption.
*
* @notes Internally, the set of lists is stored in a rocksdb database,
* mapping keys to values. Each "value" is the list itself, storing
* some kind of internal representation of the data. All the
* representation details are handled by the RedisListIterator class.
* The present file should be oblivious to the representation details,
* handling only the client (Redis) API, and the calls to rocksdb.
*
* @TODO Presently, all operations take at least O(NV) time where
* N is the number of elements in the list, and V is the average
* number of bytes per value in the list. So maybe, with merge operator
* we can improve this to an optimal O(V) amortized time, since we
* wouldn't have to read and re-write the entire list.
*
* @author Deon Nicholas (dnicholas@fb.com)
* Copyright 2013 Facebook
*/
#include "redis_lists.h"
#include <iostream>
#include <memory>
#include <cmath>
#include "leveldb/slice.h"
#include "util/coding.h"
namespace leveldb
{
/// Constructors
RedisLists::RedisLists(const std::string& db_path,
Options options, bool destructive)
: put_option_(),
get_option_() {
// Store the name of the database
db_name_ = db_path;
// If destructive, destroy the DB before re-opening it.
if (destructive) {
DestroyDB(db_name_, Options());
}
// Now open and deal with the db
DB* db;
Status s = DB::Open(options, db_name_, &db);
if (!s.ok()) {
std::cerr << "ERROR " << s.ToString() << std::endl;
assert(false);
}
db_ = std::unique_ptr<DB>(db);
}
/// Accessors
// Number of elements in the list associated with key
// : throws RedisListException
int RedisLists::Length(const std::string& key) {
// Extract the string data representing the list.
std::string data;
db_->Get(get_option_, key, &data);
// Return the length
RedisListIterator it(data);
return it.Length();
}
// Get the element at the specified index in the (list: key)
// Returns <empty> ("") on out-of-bounds
// : throws RedisListException
bool RedisLists::Index(const std::string& key, int32_t index,
std::string* result) {
// Extract the string data representing the list.
std::string data;
db_->Get(get_option_, key, &data);
// Handle REDIS negative indices (from the end); fast iff Length() takes O(1)
if (index < 0) {
index = Length(key) - (-index); //replace (-i) with (N-i).
}
// Iterate through the list until the desired index is found.
int curIndex = 0;
RedisListIterator it(data);
while(curIndex < index && !it.Done()) {
++curIndex;
it.Skip();
}
// If we actually found the index
if (curIndex == index && !it.Done()) {
Slice elem;
it.GetCurrent(&elem);
if (result != NULL) {
*result = elem.ToString();
}
return true;
} else {
return false;
}
}
// Return a truncated version of the list.
// First, negative values for first/last are interpreted as "end of list".
// So, if first == -1, then it is re-set to index: (Length(key) - 1)
// Then, return exactly those indices i such that first <= i <= last.
// : throws RedisListException
std::vector<std::string> RedisLists::Range(const std::string& key,
int32_t first, int32_t last) {
// Extract the string data representing the list.
std::string data;
db_->Get(get_option_, key, &data);
// Handle negative bounds (-1 means last element, etc.)
int listLen = Length(key);
if (first < 0) {
first = listLen - (-first); // Replace (-x) with (N-x)
}
if (last < 0) {
last = listLen - (-last);
}
// Verify bounds (and truncate the range so that it is valid)
first = std::max(first, 0);
last = std::min(last, listLen-1);
int len = std::max(last-first+1, 0);
// Initialize the resulting list
std::vector<std::string> result(len);
// Traverse the list and update the vector
int curIdx = 0;
Slice elem;
for (RedisListIterator it(data); !it.Done() && curIdx<=last; it.Skip()) {
if (first <= curIdx && curIdx <= last) {
it.GetCurrent(&elem);
result[curIdx-first].assign(elem.data(),elem.size());
}
++curIdx;
}
// Return the result. Might be empty
return result;
}
// Print the (list: key) out to stdout. For debugging mostly. Public for now.
void RedisLists::Print(const std::string& key) {
// Extract the string data representing the list.
std::string data;
db_->Get(get_option_, key, &data);
// Iterate through the list and print the items
Slice elem;
for (RedisListIterator it(data); !it.Done(); it.Skip()) {
it.GetCurrent(&elem);
std::cout << "ITEM " << elem.ToString() << std::endl;
}
//Now print the byte data
RedisListIterator it(data);
std::cout << "==Printing data==" << std::endl;
std::cout << data.size() << std::endl;
std::cout << it.Size() << " " << it.Length() << std::endl;
Slice result = it.WriteResult();
std::cout << result.data() << std::endl;
if (true) {
std::cout << "size: " << result.size() << std::endl;
const char* val = result.data();
for(int i=0; i<(int)result.size(); ++i) {
std::cout << (int)val[i] << " " << (val[i]>=32?val[i]:' ') << std::endl;
}
std::cout << std::endl;
}
}
/// Insert/Update Functions
/// Note: The "real" insert function is private. See below.
// InsertBefore and InsertAfter are simply wrappers around the Insert function.
int RedisLists::InsertBefore(const std::string& key, const std::string& pivot,
const std::string& value) {
return Insert(key, pivot, value, false);
}
int RedisLists::InsertAfter(const std::string& key, const std::string& pivot,
const std::string& value) {
return Insert(key, pivot, value, true);
}
// Prepend value onto beginning of (list: key)
// : throws RedisListException
int RedisLists::PushLeft(const std::string& key, const std::string& value) {
// Get the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Construct the result
RedisListIterator it(data);
it.Reserve(it.Size() + it.SizeOf(value));
it.InsertElement(value);
// Push the data back to the db and return the length
db_->Put(put_option_, key, it.WriteResult());
return it.Length();
}
// Append value onto end of (list: key)
// TODO: Make this O(1) time. Might require MergeOperator.
// : throws RedisListException
int RedisLists::PushRight(const std::string& key, const std::string& value) {
// Get the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Create an iterator to the data and seek to the end.
RedisListIterator it(data);
it.Reserve(it.Size() + it.SizeOf(value));
while (!it.Done()) {
it.Push(); // Write each element as we go
}
// Insert the new element at the current position (the end)
it.InsertElement(value);
// Push it back to the db, and return length
db_->Put(put_option_, key, it.WriteResult());
return it.Length();
}
// Set (list: key)[idx] = val. Return true on success, false on fail.
// : throws RedisListException
bool RedisLists::Set(const std::string& key, int32_t index,
const std::string& value) {
// Get the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Handle negative index for REDIS (meaning -index from end of list)
if (index < 0) {
index = Length(key) - (-index);
}
// Iterate through the list until we find the element we want
int curIndex = 0;
RedisListIterator it(data);
it.Reserve(it.Size() + it.SizeOf(value)); // Over-estimate is fine
while(curIndex < index && !it.Done()) {
it.Push();
++curIndex;
}
// If not found, return false (this occurs when index was invalid)
if (it.Done() || curIndex != index) {
return false;
}
// Write the new element value, and drop the previous element value
it.InsertElement(value);
it.Skip();
// Write the data to the database
// Check status, since it needs to return true/false guarantee
Status s = db_->Put(put_option_, key, it.WriteResult());
// Success
return s.ok();
}
/// Delete / Remove / Pop functions
// Trim (list: key) so that it will only contain the indices from start..stop
// Invalid indices will not generate an error, just empty,
// or the portion of the list that fits in this interval
// : throws RedisListException
bool RedisLists::Trim(const std::string& key, int32_t start, int32_t stop) {
// Get the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Handle negative indices in REDIS
int listLen = Length(key);
if (start < 0) {
start = listLen - (-start);
}
if (stop < 0) {
stop = listLen - (-stop);
}
// Truncate bounds to only fit in the list
start = std::max(start, 0);
stop = std::min(stop, listLen-1);
// Construct an iterator for the list. Drop all undesired elements.
int curIndex = 0;
RedisListIterator it(data);
it.Reserve(it.Size()); // Over-estimate
while(!it.Done()) {
// If not within the range, just skip the item (drop it).
// Otherwise, continue as usual.
if (start <= curIndex && curIndex <= stop) {
it.Push();
} else {
it.Skip();
}
// Increment the current index
++curIndex;
}
// Write the (possibly empty) result to the database
Status s = db_->Put(put_option_, key, it.WriteResult());
// Return true as long as the write succeeded
return s.ok();
}
// Return and remove the first element in the list (or "" if empty)
// : throws RedisListException
bool RedisLists::PopLeft(const std::string& key, std::string* result) {
// Get the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Point to first element in the list (if it exists), and get its value/size
RedisListIterator it(data);
if (it.Length() > 0) { // Proceed only if list is non-empty
Slice elem;
it.GetCurrent(&elem); // Store the value of the first element
it.Reserve(it.Size() - it.SizeOf(elem));
it.Skip(); // DROP the first item and move to next
// Update the db
db_->Put(put_option_, key, it.WriteResult());
// Return the value
if (result != NULL) {
*result = elem.ToString();
}
return true;
} else {
return false;
}
}
// Remove and return the last element in the list (or "" if empty)
// TODO: Make this O(1). Might require MergeOperator.
// : throws RedisListException
bool RedisLists::PopRight(const std::string& key, std::string* result) {
// Extract the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Construct an iterator to the data and move to last element
RedisListIterator it(data);
it.Reserve(it.Size());
int len = it.Length();
int curIndex = 0;
while(curIndex < (len-1) && !it.Done()) {
it.Push();
++curIndex;
}
// Extract and drop/skip the last element
if (curIndex == len-1) {
assert(!it.Done()); // Sanity check. Should not have ended here.
// Extract and pop the element
Slice elem;
it.GetCurrent(&elem); // Save value of element.
it.Skip(); // Skip the element
// Write the result to the database
db_->Put(put_option_, key, it.WriteResult());
// Return the value
if (result != NULL) {
*result = elem.ToString();
}
return true;
} else {
// Must have been an empty list
assert(it.Done() && len==0 && curIndex == 0);
return false;
}
}
// Remove the (first or last) "num" occurrences of value in (list: key)
// : throws RedisListException
int RedisLists::Remove(const std::string& key, int32_t num,
const std::string& value) {
// Negative num ==> RemoveLast; Positive num ==> Remove First
if (num < 0) {
return RemoveLast(key, -num, value);
} else if (num > 0) {
return RemoveFirst(key, num, value);
} else {
return RemoveFirst(key, Length(key), value);
}
}
// Remove the first "num" occurrences of value in (list: key).
// : throws RedisListException
int RedisLists::RemoveFirst(const std::string& key, int32_t num,
const std::string& value) {
// Ensure that the number is positive
assert(num >= 0);
// Extract the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Traverse the list, appending all but the desired occurrences of value
int numSkipped = 0; // Keep track of the number of times value is seen
Slice elem;
RedisListIterator it(data);
it.Reserve(it.Size());
while (!it.Done()) {
it.GetCurrent(&elem);
if (elem == value && numSkipped < num) {
// Drop this item if desired
it.Skip();
++numSkipped;
} else {
// Otherwise keep the item and proceed as normal
it.Push();
}
}
// Put the result back to the database
db_->Put(put_option_, key, it.WriteResult());
// Return the number of elements removed
return numSkipped;
}
// Remove the last "num" occurrences of value in (list: key).
// TODO: I traverse the list 2x. Make faster. Might require MergeOperator.
// : throws RedisListException
int RedisLists::RemoveLast(const std::string& key, int32_t num,
const std::string& value) {
// Ensure that the number is positive
assert(num >= 0);
// Extract the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Temporary variable to hold the "current element" in the blocks below
Slice elem;
// Count the total number of occurrences of value
int totalOccs = 0;
for (RedisListIterator it(data); !it.Done(); it.Skip()) {
it.GetCurrent(&elem);
if (elem == value) {
++totalOccs;
}
}
// Construct an iterator to the data. Reserve enough space for the result.
RedisListIterator it(data);
int bytesRemoved = std::min(num,totalOccs)*it.SizeOf(value);
it.Reserve(it.Size() - bytesRemoved);
// Traverse the list, appending all but the desired occurrences of value.
// Note: "Drop the last k occurrences" is equivalent to
// "keep only the first n-k occurrences", where n is total occurrences.
int numKept = 0; // Keep track of the number of times value is kept
while(!it.Done()) {
it.GetCurrent(&elem);
// If we are within the deletion range and equal to value, drop it.
// Otherwise, append/keep/push it.
if (elem == value) {
if (numKept < totalOccs - num) {
it.Push();
++numKept;
} else {
it.Skip();
}
} else {
// Always append the others
it.Push();
}
}
// Put the result back to the database
db_->Put(put_option_, key, it.WriteResult());
// Return the number of elements removed
return totalOccs - numKept;
}
/// Private functions
// Insert element value into (list: key), right before/after
// the first occurrence of pivot
// : throws RedisListException
int RedisLists::Insert(const std::string& key, const std::string& pivot,
const std::string& value, bool insert_after) {
// Get the original list data
std::string data;
db_->Get(get_option_, key, &data);
// Construct an iterator to the data and reserve enough space for result.
RedisListIterator it(data);
it.Reserve(it.Size() + it.SizeOf(value));
// Iterate through the list until we find the element we want
Slice elem;
bool found = false;
while(!it.Done() && !found) {
it.GetCurrent(&elem);
// When we find the element, insert the element and mark found
if (elem == pivot) { // Found it!
found = true;
if (insert_after == true) { // Skip one more, if inserting after it
it.Push();
}
it.InsertElement(value);
} else {
it.Push();
}
}
// Put the data (string) into the database
if (found) {
db_->Put(put_option_, key, it.WriteResult());
}
// Returns the new (possibly unchanged) length of the list
return it.Length();
}
}

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/**
* A (persistent) Redis API built using the rocksdb backend.
* Implements Redis Lists as described on: http://redis.io/commands#list
*
* @throws All functions may throw a RedisListException
*
* @author Deon Nicholas (dnicholas@fb.com)
* Copyright 2013 Facebook
*/
#include <string>
#include "leveldb/db.h"
#include "redis_list_iterator.h"
#include "redis_list_exception.h"
namespace leveldb {
/// The Redis functionality (see http://redis.io/commands#list)
/// All functions may THROW a RedisListException
class RedisLists {
public: // Constructors / Destructors
/// Construct a new RedisLists database, with name/path of db.
/// Will clear the database on open iff destructive is true (default false).
/// Otherwise, it will restore saved changes.
/// May throw RedisListException
RedisLists(const std::string& db_path,
Options options, bool destructive = false);
public: // Accessors
/// The number of items in (list: key)
int Length(const std::string& key);
/// Search the list for the (index)'th item (0-based) in (list:key)
/// A negative index indicates: "from end-of-list"
/// If index is within range: return true, and return the value in *result.
/// If (index < -length OR index>=length), then index is out of range:
/// return false (and *result is left unchanged)
/// May throw RedisListException
bool Index(const std::string& key, int32_t index,
std::string* result);
/// Return (list: key)[first..last] (inclusive)
/// May throw RedisListException
std::vector<std::string> Range(const std::string& key,
int32_t first, int32_t last);
/// Prints the entire (list: key), for debugging.
void Print(const std::string& key);
public: // Insert/Update
/// Insert value before/after pivot in (list: key). Return the length.
/// May throw RedisListException
int InsertBefore(const std::string& key, const std::string& pivot,
const std::string& value);
int InsertAfter(const std::string& key, const std::string& pivot,
const std::string& value);
/// Push / Insert value at beginning/end of the list. Return the length.
/// May throw RedisListException
int PushLeft(const std::string& key, const std::string& value);
int PushRight(const std::string& key, const std::string& value);
/// Set (list: key)[idx] = val. Return true on success, false on fail
/// May throw RedisListException
bool Set(const std::string& key, int32_t index, const std::string& value);
public: // Delete / Remove / Pop / Trim
/// Trim (list: key) so that it will only contain the indices from start..stop
/// Returns true on success
/// May throw RedisListException
bool Trim(const std::string& key, int32_t start, int32_t stop);
/// If list is empty, return false and leave *result unchanged.
/// Else, remove the first/last elem, store it in *result, and return true
bool PopLeft(const std::string& key, std::string* result); // First
bool PopRight(const std::string& key, std::string* result); // Last
/// Remove the first (or last) num occurrences of value from the list (key)
/// Return the number of elements removed.
/// May throw RedisListException
int Remove(const std::string& key, int32_t num,
const std::string& value);
int RemoveFirst(const std::string& key, int32_t num,
const std::string& value);
int RemoveLast(const std::string& key, int32_t num,
const std::string& value);
private: // Private Functions
/// Calls InsertBefore or InsertAfter
int Insert(const std::string& key, const std::string& pivot,
const std::string& value, bool insert_after);
private:
std::string db_name_; // The actual database name/path
WriteOptions put_option_;
ReadOptions get_option_;
/// The backend rocksdb database.
/// Map : key --> list
/// where a list is a sequence of elements
/// and an element is a 4-byte integer (n), followed by n bytes of data
std::unique_ptr<DB> db_;
};
} // namespace leveldb

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/**
* A test harness for the Redis API built on rocksdb.
*
* USAGE: Build with: "make redis_test" (in rocksdb directory).
* Run unit tests with: "./redis_test"
* Manual/Interactive user testing: "./redis_test -m"
* Manual user testing + restart database: "./redis_test -m -d"
*
* TODO: Add LARGE random test cases to verify efficiency and scalability
*
* @author Deon Nicholas (dnicholas@fb.com)
* Copyright 2013 Facebook
*/
#include <iostream>
#include <cctype>
#include "redis_lists.h"
#include "util/testharness.h"
#include "util/random.h"
using namespace leveldb;
using namespace std;
namespace leveldb {
class RedisListsTest {
public:
static const string kDefaultDbName;
static Options options;
RedisListsTest() {
options.create_if_missing = true;
}
};
const string RedisListsTest::kDefaultDbName = "/tmp/redisdefaultdb/";
Options RedisListsTest::options = Options();
// operator== and operator<< are defined below for vectors (lists)
// Needed for ASSERT_EQ
// Compare two lists for equality.
bool operator==(const std::vector<std::string>& a,
const std::vector<std::string>& b) {
if (a.size() != b.size()) {
return false;
}
int n = a.size();
for (int i=0; i<n; ++i) {
if (a[i] != b[i]) {
return false;
}
}
return true;
}
// Print out a list
ostream& operator<<(ostream& out, const std::vector<std::string>& vec) {
out << "[";
int n = vec.size();
for(int i=0; i<n; ++i) {
if (i > 0) {
out << ", ";
}
out << vec[i];
}
out << "]";
return out;
}
/// THE TEST CASES BEGIN HERE
// PushRight, Length, Index, Range
TEST(RedisListsTest, SimpleTest) {
RedisLists redis(kDefaultDbName, options, true); // Destructive
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// Simple PushRight (should return the new length each time)
ASSERT_EQ(redis.PushRight("k1", "v1"), 1);
ASSERT_EQ(redis.PushRight("k1", "v2"), 2);
ASSERT_EQ(redis.PushRight("k1", "v3"), 3);
// Check Length and Index() functions
ASSERT_EQ(redis.Length("k1"), 3); // Check length
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "v1"); // Check valid indices
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "v2");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "v3");
// Check range function and vectors
std::vector<std::string> result = redis.Range("k1", 0, 2); // Get the list
std::vector<std::string> expected_result(3);
expected_result[0] = "v1";
expected_result[1] = "v2";
expected_result[2] = "v3";
ASSERT_EQ(result, expected_result); // Uses my overloaded operator==() above
}
// PushLeft, Length, Index, Range
TEST(RedisListsTest, SimpleTest2) {
RedisLists redis(kDefaultDbName, options, true); // Destructive
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// Simple PushRight
ASSERT_EQ(redis.PushLeft("k1", "v3"), 1);
ASSERT_EQ(redis.PushLeft("k1", "v2"), 2);
ASSERT_EQ(redis.PushLeft("k1", "v1"), 3);
// Check Length and Index() functions
ASSERT_EQ(redis.Length("k1"), 3); // Check length
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "v1"); // Check valid indices
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "v2");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "v3");
// Check range function and vectors
std::vector<std::string> result = redis.Range("k1", 0, 2); // Get the list
std::vector<std::string> expected_result(3);
expected_result[0] = "v1";
expected_result[1] = "v2";
expected_result[2] = "v3";
ASSERT_EQ(result, expected_result); // Uses my overloaded operator==() above
}
// Exhaustive test of the Index() function
TEST(RedisListsTest, IndexTest) {
RedisLists redis(kDefaultDbName, options, true); // Destructive
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// Empty Index check (return empty and should not crash or edit tempv)
tempv = "yo";
ASSERT_TRUE(!redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "yo");
ASSERT_TRUE(!redis.Index("fda", 3, &tempv));
ASSERT_EQ(tempv, "yo");
ASSERT_TRUE(!redis.Index("random", -12391, &tempv));
ASSERT_EQ(tempv, "yo");
// Simple Pushes (will yield: [v6, v4, v4, v1, v2, v3]
redis.PushRight("k1", "v1");
redis.PushRight("k1", "v2");
redis.PushRight("k1", "v3");
redis.PushLeft("k1", "v4");
redis.PushLeft("k1", "v4");
redis.PushLeft("k1", "v6");
// Simple, non-negative indices
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "v6");
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "v4");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "v4");
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "v1");
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "v2");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "v3");
// Negative indices
ASSERT_TRUE(redis.Index("k1", -6, &tempv));
ASSERT_EQ(tempv, "v6");
ASSERT_TRUE(redis.Index("k1", -5, &tempv));
ASSERT_EQ(tempv, "v4");
ASSERT_TRUE(redis.Index("k1", -4, &tempv));
ASSERT_EQ(tempv, "v4");
ASSERT_TRUE(redis.Index("k1", -3, &tempv));
ASSERT_EQ(tempv, "v1");
ASSERT_TRUE(redis.Index("k1", -2, &tempv));
ASSERT_EQ(tempv, "v2");
ASSERT_TRUE(redis.Index("k1", -1, &tempv));
ASSERT_EQ(tempv, "v3");
// Out of bounds (return empty, no crash)
ASSERT_TRUE(!redis.Index("k1", 6, &tempv));
ASSERT_TRUE(!redis.Index("k1", 123219, &tempv));
ASSERT_TRUE(!redis.Index("k1", -7, &tempv));
ASSERT_TRUE(!redis.Index("k1", -129, &tempv));
}
// Exhaustive test of the Range() function
TEST(RedisListsTest, RangeTest) {
RedisLists redis(kDefaultDbName, options, true); // Destructive
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// Simple Pushes (will yield: [v6, v4, v4, v1, v2, v3])
redis.PushRight("k1", "v1");
redis.PushRight("k1", "v2");
redis.PushRight("k1", "v3");
redis.PushLeft("k1", "v4");
redis.PushLeft("k1", "v4");
redis.PushLeft("k1", "v6");
// Sanity check (check the length; make sure it's 6)
ASSERT_EQ(redis.Length("k1"), 6);
// Simple range
std::vector<std::string> res = redis.Range("k1", 1, 4);
ASSERT_EQ((int)res.size(), 4);
ASSERT_EQ(res[0], "v4");
ASSERT_EQ(res[1], "v4");
ASSERT_EQ(res[2], "v1");
ASSERT_EQ(res[3], "v2");
// Negative indices (i.e.: measured from the end)
res = redis.Range("k1", 2, -1);
ASSERT_EQ((int)res.size(), 4);
ASSERT_EQ(res[0], "v4");
ASSERT_EQ(res[1], "v1");
ASSERT_EQ(res[2], "v2");
ASSERT_EQ(res[3], "v3");
res = redis.Range("k1", -6, -4);
ASSERT_EQ((int)res.size(), 3);
ASSERT_EQ(res[0], "v6");
ASSERT_EQ(res[1], "v4");
ASSERT_EQ(res[2], "v4");
res = redis.Range("k1", -1, 5);
ASSERT_EQ((int)res.size(), 1);
ASSERT_EQ(res[0], "v3");
// Partial / Broken indices
res = redis.Range("k1", -3, 1000000);
ASSERT_EQ((int)res.size(), 3);
ASSERT_EQ(res[0], "v1");
ASSERT_EQ(res[1], "v2");
ASSERT_EQ(res[2], "v3");
res = redis.Range("k1", -1000000, 1);
ASSERT_EQ((int)res.size(), 2);
ASSERT_EQ(res[0], "v6");
ASSERT_EQ(res[1], "v4");
// Invalid indices
res = redis.Range("k1", 7, 9);
ASSERT_EQ((int)res.size(), 0);
res = redis.Range("k1", -8, -7);
ASSERT_EQ((int)res.size(), 0);
res = redis.Range("k1", 3, 2);
ASSERT_EQ((int)res.size(), 0);
res = redis.Range("k1", 5, -2);
ASSERT_EQ((int)res.size(), 0);
// Range matches Index
res = redis.Range("k1", -6, -4);
ASSERT_TRUE(redis.Index("k1", -6, &tempv));
ASSERT_EQ(tempv, res[0]);
ASSERT_TRUE(redis.Index("k1", -5, &tempv));
ASSERT_EQ(tempv, res[1]);
ASSERT_TRUE(redis.Index("k1", -4, &tempv));
ASSERT_EQ(tempv, res[2]);
// Last check
res = redis.Range("k1", 0, -6);
ASSERT_EQ((int)res.size(), 1);
ASSERT_EQ(res[0], "v6");
}
// Exhaustive test for InsertBefore(), and InsertAfter()
TEST(RedisListsTest, InsertTest) {
RedisLists redis(kDefaultDbName, options, true);
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// Insert on empty list (return 0, and do not crash)
ASSERT_EQ(redis.InsertBefore("k1", "non-exist", "a"), 0);
ASSERT_EQ(redis.InsertAfter("k1", "other-non-exist", "c"), 0);
ASSERT_EQ(redis.Length("k1"), 0);
// Push some preliminary stuff [g, f, e, d, c, b, a]
redis.PushLeft("k1", "a");
redis.PushLeft("k1", "b");
redis.PushLeft("k1", "c");
redis.PushLeft("k1", "d");
redis.PushLeft("k1", "e");
redis.PushLeft("k1", "f");
redis.PushLeft("k1", "g");
ASSERT_EQ(redis.Length("k1"), 7);
// Test InsertBefore
int newLength = redis.InsertBefore("k1", "e", "hello");
ASSERT_EQ(newLength, 8);
ASSERT_EQ(redis.Length("k1"), newLength);
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "f");
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "e");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "hello");
// Test InsertAfter
newLength = redis.InsertAfter("k1", "c", "bye");
ASSERT_EQ(newLength, 9);
ASSERT_EQ(redis.Length("k1"), newLength);
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "bye");
// Test bad value on InsertBefore
newLength = redis.InsertBefore("k1", "yo", "x");
ASSERT_EQ(newLength, 9);
ASSERT_EQ(redis.Length("k1"), newLength);
// Test bad value on InsertAfter
newLength = redis.InsertAfter("k1", "xxxx", "y");
ASSERT_EQ(newLength, 9);
ASSERT_EQ(redis.Length("k1"), newLength);
// Test InsertBefore beginning
newLength = redis.InsertBefore("k1", "g", "begggggggggggggggg");
ASSERT_EQ(newLength, 10);
ASSERT_EQ(redis.Length("k1"), newLength);
// Test InsertAfter end
newLength = redis.InsertAfter("k1", "a", "enddd");
ASSERT_EQ(newLength, 11);
ASSERT_EQ(redis.Length("k1"), newLength);
// Make sure nothing weird happened.
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "begggggggggggggggg");
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "g");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "f");
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "hello");
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "e");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "d");
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "c");
ASSERT_TRUE(redis.Index("k1", 7, &tempv));
ASSERT_EQ(tempv, "bye");
ASSERT_TRUE(redis.Index("k1", 8, &tempv));
ASSERT_EQ(tempv, "b");
ASSERT_TRUE(redis.Index("k1", 9, &tempv));
ASSERT_EQ(tempv, "a");
ASSERT_TRUE(redis.Index("k1", 10, &tempv));
ASSERT_EQ(tempv, "enddd");
}
// Exhaustive test of Set function
TEST(RedisListsTest, SetTest) {
RedisLists redis(kDefaultDbName, options, true);
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// Set on empty list (return false, and do not crash)
ASSERT_EQ(redis.Set("k1", 7, "a"), false);
ASSERT_EQ(redis.Set("k1", 0, "a"), false);
ASSERT_EQ(redis.Set("k1", -49, "cx"), false);
ASSERT_EQ(redis.Length("k1"), 0);
// Push some preliminary stuff [g, f, e, d, c, b, a]
redis.PushLeft("k1", "a");
redis.PushLeft("k1", "b");
redis.PushLeft("k1", "c");
redis.PushLeft("k1", "d");
redis.PushLeft("k1", "e");
redis.PushLeft("k1", "f");
redis.PushLeft("k1", "g");
ASSERT_EQ(redis.Length("k1"), 7);
// Test Regular Set
ASSERT_TRUE(redis.Set("k1", 0, "0"));
ASSERT_TRUE(redis.Set("k1", 3, "3"));
ASSERT_TRUE(redis.Set("k1", 6, "6"));
ASSERT_TRUE(redis.Set("k1", 2, "2"));
ASSERT_TRUE(redis.Set("k1", 5, "5"));
ASSERT_TRUE(redis.Set("k1", 1, "1"));
ASSERT_TRUE(redis.Set("k1", 4, "4"));
ASSERT_EQ(redis.Length("k1"), 7); // Size should not change
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "0");
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "1");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "2");
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "3");
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "4");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "5");
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "6");
// Set with negative indices
ASSERT_TRUE(redis.Set("k1", -7, "a"));
ASSERT_TRUE(redis.Set("k1", -4, "d"));
ASSERT_TRUE(redis.Set("k1", -1, "g"));
ASSERT_TRUE(redis.Set("k1", -5, "c"));
ASSERT_TRUE(redis.Set("k1", -2, "f"));
ASSERT_TRUE(redis.Set("k1", -6, "b"));
ASSERT_TRUE(redis.Set("k1", -3, "e"));
ASSERT_EQ(redis.Length("k1"), 7); // Size should not change
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "a");
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "b");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "c");
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "d");
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "e");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "f");
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "g");
// Bad indices (just out-of-bounds / off-by-one check)
ASSERT_EQ(redis.Set("k1", -8, "off-by-one in negative index"), false);
ASSERT_EQ(redis.Set("k1", 7, "off-by-one-error in positive index"), false);
ASSERT_EQ(redis.Set("k1", 43892, "big random index should fail"), false);
ASSERT_EQ(redis.Set("k1", -21391, "large negative index should fail"), false);
// One last check (to make sure nothing weird happened)
ASSERT_EQ(redis.Length("k1"), 7); // Size should not change
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "a");
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "b");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "c");
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "d");
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "e");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "f");
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "g");
}
// Testing Insert, Push, and Set, in a mixed environment
TEST(RedisListsTest, InsertPushSetTest) {
RedisLists redis(kDefaultDbName, options, true); // Destructive
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// A series of pushes and insertions
// Will result in [newbegin, z, a, aftera, x, newend]
// Also, check the return value sometimes (should return length)
int lengthCheck;
lengthCheck = redis.PushLeft("k1", "a");
ASSERT_EQ(lengthCheck, 1);
redis.PushLeft("k1", "z");
redis.PushRight("k1", "x");
lengthCheck = redis.InsertAfter("k1", "a", "aftera");
ASSERT_EQ(lengthCheck , 4);
redis.InsertBefore("k1", "z", "newbegin"); // InsertBefore beginning of list
redis.InsertAfter("k1", "x", "newend"); // InsertAfter end of list
// Check
std::vector<std::string> res = redis.Range("k1", 0, -1); // Get the list
ASSERT_EQ((int)res.size(), 6);
ASSERT_EQ(res[0], "newbegin");
ASSERT_EQ(res[5], "newend");
ASSERT_EQ(res[3], "aftera");
// Testing duplicate values/pivots (multiple occurrences of 'a')
ASSERT_TRUE(redis.Set("k1", 0, "a")); // [a, z, a, aftera, x, newend]
redis.InsertAfter("k1", "a", "happy"); // [a, happy, z, a, aftera, ...]
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "happy");
redis.InsertBefore("k1", "a", "sad"); // [sad, a, happy, z, a, aftera, ...]
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "sad");
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "happy");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "aftera");
redis.InsertAfter("k1", "a", "zz"); // [sad, a, zz, happy, z, a, aftera, ...]
ASSERT_TRUE(redis.Index("k1", 2, &tempv));
ASSERT_EQ(tempv, "zz");
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "aftera");
ASSERT_TRUE(redis.Set("k1", 1, "nota")); // [sad, nota, zz, happy, z, a, ...]
redis.InsertBefore("k1", "a", "ba"); // [sad, nota, zz, happy, z, ba, a, ...]
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "z");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "ba");
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "a");
// We currently have: [sad, nota, zz, happy, z, ba, a, aftera, x, newend]
// redis.Print("k1"); // manually check
// Test Inserting before/after non-existent values
lengthCheck = redis.Length("k1"); // Ensure that the length doesnt change
ASSERT_EQ(lengthCheck, 10);
ASSERT_EQ(redis.InsertBefore("k1", "non-exist", "randval"), lengthCheck);
ASSERT_EQ(redis.InsertAfter("k1", "nothing", "a"), lengthCheck);
ASSERT_EQ(redis.InsertAfter("randKey", "randVal", "ranValue"), 0); // Empty
ASSERT_EQ(redis.Length("k1"), lengthCheck); // The length should not change
// Simply Test the Set() function
redis.Set("k1", 5, "ba2");
redis.InsertBefore("k1", "ba2", "beforeba2");
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "z");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "beforeba2");
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "ba2");
ASSERT_TRUE(redis.Index("k1", 7, &tempv));
ASSERT_EQ(tempv, "a");
// We have: [sad, nota, zz, happy, z, beforeba2, ba2, a, aftera, x, newend]
// Set() with negative indices
redis.Set("k1", -1, "endprank");
ASSERT_TRUE(!redis.Index("k1", 11, &tempv));
ASSERT_TRUE(redis.Index("k1", 10, &tempv));
ASSERT_EQ(tempv, "endprank"); // Ensure Set worked correctly
redis.Set("k1", -11, "t");
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "t");
// Test out of bounds Set
ASSERT_EQ(redis.Set("k1", -12, "ssd"), false);
ASSERT_EQ(redis.Set("k1", 11, "sasd"), false);
ASSERT_EQ(redis.Set("k1", 1200, "big"), false);
}
// Testing Trim, Pop
TEST(RedisListsTest, TrimPopTest) {
RedisLists redis(kDefaultDbName, options, true); // Destructive
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// A series of pushes and insertions
// Will result in [newbegin, z, a, aftera, x, newend]
redis.PushLeft("k1", "a");
redis.PushLeft("k1", "z");
redis.PushRight("k1", "x");
redis.InsertBefore("k1", "z", "newbegin"); // InsertBefore start of list
redis.InsertAfter("k1", "x", "newend"); // InsertAfter end of list
redis.InsertAfter("k1", "a", "aftera");
// Simple PopLeft/Right test
ASSERT_TRUE(redis.PopLeft("k1", &tempv));
ASSERT_EQ(tempv, "newbegin");
ASSERT_EQ(redis.Length("k1"), 5);
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "z");
ASSERT_TRUE(redis.PopRight("k1", &tempv));
ASSERT_EQ(tempv, "newend");
ASSERT_EQ(redis.Length("k1"), 4);
ASSERT_TRUE(redis.Index("k1", -1, &tempv));
ASSERT_EQ(tempv, "x");
// Now have: [z, a, aftera, x]
// Test Trim
ASSERT_TRUE(redis.Trim("k1", 0, -1)); // [z, a, aftera, x] (do nothing)
ASSERT_EQ(redis.Length("k1"), 4);
ASSERT_TRUE(redis.Trim("k1", 0, 2)); // [z, a, aftera]
ASSERT_EQ(redis.Length("k1"), 3);
ASSERT_TRUE(redis.Index("k1", -1, &tempv));
ASSERT_EQ(tempv, "aftera");
ASSERT_TRUE(redis.Trim("k1", 1, 1)); // [a]
ASSERT_EQ(redis.Length("k1"), 1);
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "a");
// Test out of bounds (empty) trim
ASSERT_TRUE(redis.Trim("k1", 1, 0));
ASSERT_EQ(redis.Length("k1"), 0);
// Popping with empty list (return empty without error)
ASSERT_TRUE(!redis.PopLeft("k1", &tempv));
ASSERT_TRUE(!redis.PopRight("k1", &tempv));
ASSERT_TRUE(redis.Trim("k1", 0, 5));
// Exhaustive Trim test (negative and invalid indices)
// Will start in [newbegin, z, a, aftera, x, newend]
redis.PushLeft("k1", "a");
redis.PushLeft("k1", "z");
redis.PushRight("k1", "x");
redis.InsertBefore("k1", "z", "newbegin"); // InsertBefore start of list
redis.InsertAfter("k1", "x", "newend"); // InsertAfter end of list
redis.InsertAfter("k1", "a", "aftera");
ASSERT_TRUE(redis.Trim("k1", -6, -1)); // Should do nothing
ASSERT_EQ(redis.Length("k1"), 6);
ASSERT_TRUE(redis.Trim("k1", 1, -2));
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "z");
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "x");
ASSERT_EQ(redis.Length("k1"), 4);
ASSERT_TRUE(redis.Trim("k1", -3, -2));
ASSERT_EQ(redis.Length("k1"), 2);
}
// Testing Remove, RemoveFirst, RemoveLast
TEST(RedisListsTest, RemoveTest) {
RedisLists redis(kDefaultDbName, options, true); // Destructive
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// A series of pushes and insertions
// Will result in [newbegin, z, a, aftera, x, newend, a, a]
redis.PushLeft("k1", "a");
redis.PushLeft("k1", "z");
redis.PushRight("k1", "x");
redis.InsertBefore("k1", "z", "newbegin"); // InsertBefore start of list
redis.InsertAfter("k1", "x", "newend"); // InsertAfter end of list
redis.InsertAfter("k1", "a", "aftera");
redis.PushRight("k1", "a");
redis.PushRight("k1", "a");
// Verify
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "newbegin");
ASSERT_TRUE(redis.Index("k1", -1, &tempv));
ASSERT_EQ(tempv, "a");
// Check RemoveFirst (Remove the first two 'a')
// Results in [newbegin, z, aftera, x, newend, a]
int numRemoved = redis.Remove("k1", 2, "a");
ASSERT_EQ(numRemoved, 2);
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "newbegin");
ASSERT_TRUE(redis.Index("k1", 1, &tempv));
ASSERT_EQ(tempv, "z");
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "newend");
ASSERT_TRUE(redis.Index("k1", 5, &tempv));
ASSERT_EQ(tempv, "a");
ASSERT_EQ(redis.Length("k1"), 6);
// Repopulate some stuff
// Results in: [x, x, x, x, x, newbegin, z, x, aftera, x, newend, a, x]
redis.PushLeft("k1", "x");
redis.PushLeft("k1", "x");
redis.PushLeft("k1", "x");
redis.PushLeft("k1", "x");
redis.PushLeft("k1", "x");
redis.PushRight("k1", "x");
redis.InsertAfter("k1", "z", "x");
// Test removal from end
numRemoved = redis.Remove("k1", -2, "x");
ASSERT_EQ(numRemoved, 2);
ASSERT_TRUE(redis.Index("k1", 8, &tempv));
ASSERT_EQ(tempv, "aftera");
ASSERT_TRUE(redis.Index("k1", 9, &tempv));
ASSERT_EQ(tempv, "newend");
ASSERT_TRUE(redis.Index("k1", 10, &tempv));
ASSERT_EQ(tempv, "a");
ASSERT_TRUE(!redis.Index("k1", 11, &tempv));
numRemoved = redis.Remove("k1", -2, "x");
ASSERT_EQ(numRemoved, 2);
ASSERT_TRUE(redis.Index("k1", 4, &tempv));
ASSERT_EQ(tempv, "newbegin");
ASSERT_TRUE(redis.Index("k1", 6, &tempv));
ASSERT_EQ(tempv, "aftera");
// We now have: [x, x, x, x, newbegin, z, aftera, newend, a]
ASSERT_EQ(redis.Length("k1"), 9);
ASSERT_TRUE(redis.Index("k1", -1, &tempv));
ASSERT_EQ(tempv, "a");
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "x");
// Test over-shooting (removing more than there exists)
numRemoved = redis.Remove("k1", -9000, "x");
ASSERT_EQ(numRemoved , 4); // Only really removed 4
ASSERT_EQ(redis.Length("k1"), 5);
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "newbegin");
numRemoved = redis.Remove("k1", 1, "x");
ASSERT_EQ(numRemoved, 0);
// Try removing ALL!
numRemoved = redis.Remove("k1", 0, "newbegin"); // REMOVE 0 will remove all!
ASSERT_EQ(numRemoved, 1);
// Removal from an empty-list
ASSERT_TRUE(redis.Trim("k1", 1, 0));
numRemoved = redis.Remove("k1", 1, "z");
ASSERT_EQ(numRemoved, 0);
}
// Test Multiple keys and Persistence
TEST(RedisListsTest, PersistenceMultiKeyTest) {
string tempv; // Used below for all Index(), PopRight(), PopLeft()
// Block one: populate a single key in the database
{
RedisLists redis(kDefaultDbName, options, true); // Destructive
// A series of pushes and insertions
// Will result in [newbegin, z, a, aftera, x, newend, a, a]
redis.PushLeft("k1", "a");
redis.PushLeft("k1", "z");
redis.PushRight("k1", "x");
redis.InsertBefore("k1", "z", "newbegin"); // InsertBefore start of list
redis.InsertAfter("k1", "x", "newend"); // InsertAfter end of list
redis.InsertAfter("k1", "a", "aftera");
redis.PushRight("k1", "a");
redis.PushRight("k1", "a");
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "aftera");
}
// Block two: make sure changes were saved and add some other key
{
RedisLists redis(kDefaultDbName, options, false); // Persistent, non-destructive
// Check
ASSERT_EQ(redis.Length("k1"), 8);
ASSERT_TRUE(redis.Index("k1", 3, &tempv));
ASSERT_EQ(tempv, "aftera");
redis.PushRight("k2", "randomkey");
redis.PushLeft("k2", "sas");
redis.PopLeft("k1", &tempv);
}
// Block three: Verify the changes from block 2
{
RedisLists redis(kDefaultDbName, options, false); // Presistent, non-destructive
// Check
ASSERT_EQ(redis.Length("k1"), 7);
ASSERT_EQ(redis.Length("k2"), 2);
ASSERT_TRUE(redis.Index("k1", 0, &tempv));
ASSERT_EQ(tempv, "z");
ASSERT_TRUE(redis.Index("k2", -2, &tempv));
ASSERT_EQ(tempv, "sas");
}
}
/// THE manual REDIS TEST begins here
/// THIS WILL ONLY OCCUR IF YOU RUN: ./redis_test -m
void MakeUpper(std::string* const s) {
int len = s->length();
for(int i=0; i<len; ++i) {
(*s)[i] = toupper((*s)[i]); // C-version defined in <ctype.h>
}
}
/// Allows the user to enter in REDIS commands into the command-line.
/// This is useful for manual / interacticve testing / debugging.
/// Use destructive=true to clean the database before use.
/// Use destructive=false to remember the previous state (i.e.: persistent)
/// Should be called from main function.
int manual_redis_test(bool destructive){
RedisLists redis(RedisListsTest::kDefaultDbName,
RedisListsTest::options,
destructive);
// TODO: Right now, please use spaces to separate each word.
// In actual redis, you can use quotes to specify compound values
// Example: RPUSH mylist "this is a compound value"
std::string command;
while(true) {
cin >> command;
MakeUpper(&command);
if (command == "LINSERT") {
std::string k, t, p, v;
cin >> k >> t >> p >> v;
MakeUpper(&t);
if (t=="BEFORE") {
std::cout << redis.InsertBefore(k, p, v) << std::endl;
} else if (t=="AFTER") {
std::cout << redis.InsertAfter(k, p, v) << std::endl;
}
} else if (command == "LPUSH") {
std::string k, v;
std::cin >> k >> v;
redis.PushLeft(k, v);
} else if (command == "RPUSH") {
std::string k, v;
std::cin >> k >> v;
redis.PushRight(k, v);
} else if (command == "LPOP") {
std::string k;
std::cin >> k;
string res;
redis.PopLeft(k, &res);
std::cout << res << std::endl;
} else if (command == "RPOP") {
std::string k;
std::cin >> k;
string res;
redis.PopRight(k, &res);
std::cout << res << std::endl;
} else if (command == "LREM") {
std::string k;
int amt;
std::string v;
std::cin >> k >> amt >> v;
std::cout << redis.Remove(k, amt, v) << std::endl;
} else if (command == "LLEN") {
std::string k;
std::cin >> k;
std::cout << redis.Length(k) << std::endl;
} else if (command == "LRANGE") {
std::string k;
int i, j;
std::cin >> k >> i >> j;
std::vector<std::string> res = redis.Range(k, i, j);
for (auto it = res.begin(); it != res.end(); ++it) {
std::cout << " " << (*it);
}
std::cout << std::endl;
} else if (command == "LTRIM") {
std::string k;
int i, j;
std::cin >> k >> i >> j;
redis.Trim(k, i, j);
} else if (command == "LSET") {
std::string k;
int idx;
std::string v;
cin >> k >> idx >> v;
redis.Set(k, idx, v);
} else if (command == "LINDEX") {
std::string k;
int idx;
std::cin >> k >> idx;
string res;
redis.Index(k, idx, &res);
std::cout << res << std::endl;
} else if (command == "PRINT") { // Added by Deon
std::string k;
cin >> k;
redis.Print(k);
} else if (command == "QUIT") {
return 0;
} else {
std::cout << "unknown command: " << command << std::endl;
}
}
}
} // namespace leveldb
// USAGE: "./redis_test" for default (unit tests)
// "./redis_test -m" for manual testing (redis command api)
// "./redis_test -m -d" for destructive manual test (erase db before use)
// Check for "want" argument in the argument list
bool found_arg(int argc, char* argv[], const char* want){
for(int i=1; i<argc; ++i){
if (strcmp(argv[i], want) == 0) {
return true;
}
}
return false;
}
// Will run unit tests.
// However, if -m is specified, it will do user manual/interactive testing
// -m -d is manual and destructive (will clear the database before use)
int main(int argc, char* argv[]) {
if (found_arg(argc, argv, "-m")) {
bool destructive = found_arg(argc, argv, "-d");
return leveldb::manual_redis_test(destructive);
} else {
return leveldb::test::RunAllTests();
}
}