X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=pv%2Fdata%2Flogicsnapshot.cpp;h=e6fd26e33b68f742a8547894487ddf7f719a5bd3;hb=479bcabe6b4d0b1f51984085d9944ce6b03ed07c;hp=5665d35f8c3d58916b3df6ed41c11227f13d39cf;hpb=5cef1ea3c6a3ed3851c631354bf9168a154179dc;p=pulseview.git

diff --git a/pv/data/logicsnapshot.cpp b/pv/data/logicsnapshot.cpp
index 5665d35f..e6fd26e3 100644
--- a/pv/data/logicsnapshot.cpp
+++ b/pv/data/logicsnapshot.cpp
@@ -70,14 +70,17 @@ void LogicSnapshot::append_payload(
 	append_payload_to_mipmap();
 }
 
-void LogicSnapshot::reallocate_mip_map(MipMapLevel &m)
+void LogicSnapshot::reallocate_mipmap_level(MipMapLevel &m)
 {
 	const uint64_t new_data_length = ((m.length + MipMapDataUnit - 1) /
 		MipMapDataUnit) * MipMapDataUnit;
 	if (new_data_length > m.data_length)
 	{
 		m.data_length = new_data_length;
-		m.data = realloc(m.data, new_data_length * _unit_size);
+
+		// Padding is added to allow for the uint64_t write word
+		m.data = realloc(m.data, new_data_length * _unit_size +
+			sizeof(uint64_t));
 	}
 }
 
@@ -98,14 +101,12 @@ void LogicSnapshot::append_payload_to_mipmap()
 	if (m0.length == prev_length)
 		return;
 
-	reallocate_mip_map(m0);
+	reallocate_mipmap_level(m0);
 
 	dest_ptr = (uint8_t*)m0.data + prev_length * _unit_size;
 
 	// Iterate through the samples to populate the first level mipmap
-	accumulator = 0;
-	diff_counter = MipMapScaleFactor;
-	const uint8_t *end_src_ptr = (uint8_t*)_data +
+	const uint8_t *const end_src_ptr = (uint8_t*)_data +
 		m0.length * _unit_size * MipMapScaleFactor;
 	for (src_ptr = (uint8_t*)_data +
 		prev_length * _unit_size * MipMapScaleFactor;
@@ -140,12 +141,12 @@ void LogicSnapshot::append_payload_to_mipmap()
 		if (m.length == prev_length)
 			break;
 
-		reallocate_mip_map(m);
+		reallocate_mipmap_level(m);
 
 		// Subsample the level lower level
 		src_ptr = (uint8_t*)ml.data +
 			_unit_size * prev_length * MipMapScaleFactor;
-		const uint8_t *end_dest_ptr =
+		const uint8_t *const end_dest_ptr =
 			(uint8_t*)m.data + _unit_size * m.length;
 		for (dest_ptr = (uint8_t*)m.data +
 			_unit_size * prev_length;
@@ -204,7 +205,10 @@ void LogicSnapshot::get_subsampled_edges(
 	{
 		//----- Continue to search -----//
 		level = min_level;
-		fast_forward = true;
+
+		// We cannot fast-forward if there is no mip-map data at
+		// at the minimum level.
+		fast_forward = (_mip_map[level].data != NULL);
 
 		if (min_length < MipMapScaleFactor)
 		{
@@ -241,7 +245,8 @@ void LogicSnapshot::get_subsampled_edges(
 			// We can fast forward only if there was no change
 			const bool sample =
 				(get_sample(index) & sig_mask) != 0;
-			fast_forward = last_sample == sample;
+			if (last_sample != sample)
+				fast_forward = false;
 		}
 
 		if (fast_forward) {