X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=pv%2Fdata%2Fsnapshot.cpp;h=6ba39d2fe9ef57b32f8e67747ccdc65d25dbf170;hb=9df8453f6809f2ce038717111979474a60d5746a;hp=f3855e06c34ce9bf7cf829b5b27085f70bcb82e7;hpb=1b1ec774978b65209ce2b454cbf81da499b797d2;p=pulseview.git

diff --git a/pv/data/snapshot.cpp b/pv/data/snapshot.cpp
index f3855e06..6ba39d2f 100644
--- a/pv/data/snapshot.cpp
+++ b/pv/data/snapshot.cpp
@@ -24,7 +24,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-using namespace boost;
+using boost::lock_guard;
+using boost::recursive_mutex;
 
 namespace pv {
 namespace data {
@@ -32,6 +33,7 @@ namespace data {
 Snapshot::Snapshot(int unit_size) :
 	_data(NULL),
 	_sample_count(0),
+	_capacity(0),
 	_unit_size(unit_size)
 {
 	lock_guard<recursive_mutex> lock(_mutex);
@@ -44,16 +46,46 @@ Snapshot::~Snapshot()
 	free(_data);
 }
 
-uint64_t Snapshot::get_sample_count()
+uint64_t Snapshot::get_sample_count() const
 {
 	lock_guard<recursive_mutex> lock(_mutex);
 	return _sample_count;
 }
 
+int Snapshot::unit_size() const
+{
+	return _unit_size;
+}
+
+void Snapshot::set_capacity(const uint64_t new_capacity)
+{
+	lock_guard<recursive_mutex> lock(_mutex);
+
+	assert(_capacity >= _sample_count);
+	if (new_capacity > _capacity) {
+		_capacity = new_capacity;
+		_data = realloc(_data, (new_capacity * _unit_size) + sizeof(uint64_t));
+	}
+}
+
+uint64_t Snapshot::capacity() const
+{
+	lock_guard<recursive_mutex> lock(_mutex);
+	return _capacity;
+}
+
 void Snapshot::append_data(void *data, uint64_t samples)
 {
 	lock_guard<recursive_mutex> lock(_mutex);
-	_data = realloc(_data, (_sample_count + samples) * _unit_size);
+
+	assert(_capacity >= _sample_count);
+
+	// Ensure there's enough capacity to copy.
+	const uint64_t free_space = _capacity - _sample_count;
+	if (free_space < samples) {
+		set_capacity(_sample_count + samples);
+	}
+
 	memcpy((uint8_t*)_data + _sample_count * _unit_size,
 		data, samples * _unit_size);
 	_sample_count += samples;