[PATCH 02/10] kernel-shark: Add getStreamColorTable()

["Yordan Karadzhov (VMware)" <y.karadz@gmail.com>]

This method provides a hash table that maps the stream Ids to
rainbow-like colors.

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 src/KsPlotTools.cpp | 33 +++++++++++++++++++++++++++++++++
 src/KsPlotTools.hpp |  2 ++
 2 files changed, 35 insertions(+)

diff --git a/src/KsPlotTools.cpp b/src/KsPlotTools.cpp
index 113a6c0..7a0450b 100644
--- a/src/KsPlotTools.cpp
+++ b/src/KsPlotTools.cpp
@@ -182,6 +182,39 @@ ColorTable getCPUColorTable()
 	return colors;
 }
 
+/**
+ * @brief Create a Hash table of Rainbow colors. The Steam Ids are
+ *	  mapped to the palette of Rainbow colors.
+ *
+ * @returns ColorTable instance.
+ */
+ColorTable getStreamColorTable()
+{
+	kshark_context *kshark_ctx(nullptr);
+	ColorTable colors;
+	Color color;
+	float alpha(.35);
+	int *streamIds;
+
+	if (!kshark_instance(&kshark_ctx))
+		return colors;
+
+	streamIds = kshark_all_streams(kshark_ctx);
+	for (int i = 0; i < kshark_ctx->n_streams; ++i) {
+		/*
+		 * Starting from index 6 provides better functioning of the
+		 * color scheme slider.
+		 */
+		color.setRainbowColor(i + 6);
+		color.blend(alpha);
+		colors[streamIds[i]] = color;
+	}
+
+	free(streamIds);
+
+	return colors;
+}
+
 /**
  * @brief Search the Hash table of Rainbow colors for a particular key (pid).
  *
diff --git a/src/KsPlotTools.hpp b/src/KsPlotTools.hpp
index 6e66373..ab28f43 100644
--- a/src/KsPlotTools.hpp
+++ b/src/KsPlotTools.hpp
@@ -78,6 +78,8 @@ ColorTable getTaskColorTable();
 
 ColorTable getCPUColorTable();
 
+ColorTable getStreamColorTable();
+
 Color getColor(ColorTable *colors, int pid);
 
 /** Represents an abstract graphical element. */
-- 
2.25.1