Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Supernode: range merge function #126

Merged
merged 2 commits into from
Apr 3, 2023
Merged

Supernode: range merge function #126

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9dc358c
range merge function
etwest Mar 21, 2023
9436ddd
improvements to range merge
etwest Mar 21, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 13 additions & 2 deletions include/supernode.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -37,6 +37,7 @@ class Supernode {

private:
size_t num_sketches;
size_t merged_sketches; // This variable tells us which sketches are good for queries post merge
size_t sketch_size;

/* collection of logn sketches to query from, since we can't query from one
Expand Down Expand Up @@ -112,10 +113,10 @@ class Supernode {
static int get_max_sketches() { return max_sketches; };

// get number of samples remaining in the Supernode
int samples_remaining() { return num_sketches - sample_idx; }
int samples_remaining() { return merged_sketches - sample_idx; }

inline bool out_of_queries() {
return sample_idx >= num_sketches;
return sample_idx >= merged_sketches;
}

inline int curr_idx() {
Expand Down Expand Up @@ -158,6 +159,16 @@ class Supernode {
*/
void merge(Supernode& other);

/**
* In-place range merge function. Updates the caller Supernode.
* The range merge only merges some of the Sketches
* This function should only be used if you know what you're doing
* @param other Supernode to merge into caller
* @param start_idx Index of first Sketch to merge
* @param num_merge How many sketches to merge
*/
void range_merge(Supernode& other, size_t start_idx, size_t num_merge);

/**
* Insert or delete an (encoded) edge into the supernode. Guaranteed to be
* processed BEFORE Boruvka starts.
Expand Down
27 changes: 19 additions & 8 deletions src/supernode.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,8 @@ size_t Supernode::bytes_size;
size_t Supernode::serialized_size;

Supernode::Supernode(uint64_t n, uint64_t seed): sample_idx(0),
n(n), seed(seed), num_sketches(max_sketches), sketch_size(Sketch::sketchSizeof()) {
n(n), seed(seed), num_sketches(max_sketches),
merged_sketches(max_sketches), sketch_size(Sketch::sketchSizeof()) {

size_t sketch_width = Sketch::column_gen(Sketch::get_failure_factor());
// generate num_sketches sketches for each supernode (read: node)
Expand Down Expand Up @@ -40,6 +41,7 @@ Supernode::Supernode(uint64_t n, uint64_t seed, std::istream &binary_in) :
}
// sample in range [beg, beg + num)
num_sketches = beg + num;
merged_sketches = num_sketches;
sample_idx = beg;

// create empty sketches, if any
Expand All @@ -59,8 +61,9 @@ Supernode::Supernode(uint64_t n, uint64_t seed, std::istream &binary_in) :
}
}

Supernode::Supernode(const Supernode& s) : sample_idx(s.sample_idx), n(s.n),
seed(s.seed), num_sketches(s.num_sketches), sketch_size(s.sketch_size) {
Supernode::Supernode(const Supernode& s) :
sample_idx(s.sample_idx), n(s.n), seed(s.seed), num_sketches(s.num_sketches),
merged_sketches(s.merged_sketches), sketch_size(s.sketch_size) {
for (size_t i = 0; i < num_sketches; ++i) {
Sketch::makeSketch(get_sketch(i), *s.get_sketch(i));
}
Expand All @@ -82,7 +85,7 @@ Supernode::~Supernode() {
}

std::pair<Edge, SampleSketchRet> Supernode::sample() {
if (sample_idx == num_sketches) throw OutOfQueriesException();
if (out_of_queries()) throw OutOfQueriesException();

std::pair<vec_t, SampleSketchRet> query_ret = get_sketch(sample_idx++)->query();
vec_t non_zero = query_ret.first;
Expand All @@ -91,7 +94,7 @@ std::pair<Edge, SampleSketchRet> Supernode::sample() {
}

std::pair<std::vector<Edge>, SampleSketchRet> Supernode::exhaustive_sample() {
if (sample_idx == num_sketches) throw OutOfQueriesException();
if (out_of_queries()) throw OutOfQueriesException();

std::pair<std::vector<vec_t>, SampleSketchRet> query_ret = get_sketch(sample_idx++)->exhaustive_query();
std::vector<Edge> edges(query_ret.first.size());
Expand All @@ -104,10 +107,18 @@ std::pair<std::vector<Edge>, SampleSketchRet> Supernode::exhaustive_sample() {

void Supernode::merge(Supernode &other) {
sample_idx = std::max(sample_idx, other.sample_idx);
num_sketches = std::min(num_sketches, other.num_sketches);
for (size_t i=sample_idx;i<num_sketches;++i) {
merged_sketches = std::min(merged_sketches, other.merged_sketches);
for (size_t i = sample_idx; i < merged_sketches; ++i)
(*get_sketch(i))+=(*other.get_sketch(i));
}

void Supernode::range_merge(Supernode& other, size_t start_idx, size_t num_merge) {
sample_idx = std::max(sample_idx, other.sample_idx);
// we trust the caller so whatever they tell us goes here
// hopefully if the caller is incorrect then this will be caught by out_of_queries()
merged_sketches = start_idx + num_merge;
for (size_t i = sample_idx; i < merged_sketches; i++)
(*get_sketch(i))+=(*other.get_sketch(i));
}
}

void Supernode::update(vec_t upd) {
Expand Down