Char Stream Request - Optimized for high rate

src/char_stream_req/char_stream_req.cpp

@@ -0,0 +1,55 @@
+/*
+ * char_stream_req.cpp
+ *
+ *  Created on: Nov 14, 2014
+ *      Author: edwardh
+ */
+
+#include <cstring>
+
+#include "char_stream_req.h"
+
+
+CharStreamReq::CharStreamReq()
+{
+    this->max_num_of_unique_chars = (unsigned char)~0 + 1;
+    this->char_occurrence_count = new unsigned int[max_num_of_unique_chars];
+
+    clearRecv();
+}
+
+CharStreamReq::~CharStreamReq()
+{
+    delete []this->char_occurrence_count;
+}
+
+
+void CharStreamReq::recv(unsigned char in_char)
+{
+    char_occurrence_count[in_char]++;
+}
+
+
+void CharStreamReq::printRecvSorted(char *outbuffer, size_t buf_size)
+{
+    size_t char_out_itr = 0;
+
+    for(unsigned int char_in_itr = 0; char_in_itr < max_num_of_unique_chars; ++char_in_itr)
+    {
+        int num_of_chars_to_output = char_occurrence_count[char_in_itr];
+        for(int duplicate_char_out_itr = 0;
+           (duplicate_char_out_itr < num_of_chars_to_output) && (char_out_itr < buf_size-1);
+           ++duplicate_char_out_itr)
+        {
+            outbuffer[char_out_itr] = char_in_itr;
+            char_out_itr++;
+        }
+    }
+
+    outbuffer[char_out_itr] = '\0';
+}
+
+void CharStreamReq::clearRecv()
+{
+    std::memset(this->char_occurrence_count, 0 ,max_num_of_unique_chars * sizeof(*char_occurrence_count));
+}

src/char_stream_req/char_stream_req.h

@@ -0,0 +1,40 @@
+/*
+ * char_stream_req.h
+ *
+ * Description:
+ * Receive a stream of characters (ASCII), accumulate them and
+ * provide the means to output them in an acceding sorted manner.
+ *
+ * Limitations:
+ * - Sorted based on the ASCII table, no special care has been done to handle upper and lower characters.
+ * - It can accumulate between 2^(sizeof(int)) to 256 * (2^(sizeof(int))) characters.
+ *
+ * Note: It is up to the application that uses this module to specify how many characters to recv
+ *       until a print is performed, followed by a clear to reset the data.
+ *
+ *
+ *  Created on: Nov 14, 2014
+ *      Author: edwardh
+ */
+
+#ifndef CHAR_STREAM_REQ_H_
+#define CHAR_STREAM_REQ_H_
+
+
+class CharStreamReq
+{
+public:
+    CharStreamReq();
+    ~CharStreamReq();
+
+    void recv(unsigned char in_char);
+    void printRecvSorted(char *outbuffer, size_t buf_size);
+    void clearRecv();
+
+private:
+    unsigned int *char_occurrence_count;
+    unsigned int  max_num_of_unique_chars;
+};
+
+
+#endif /* CHAR_STREAM_REQ_H_ */

unit_tester/build/mk_common/utest_config_production_path.mk

@@ -1,16 +1,18 @@
-#
-#
-#
-
-#	When all source files in a folder are under tests, it is prefered to add the folder instead of adding individual source files.
-SRC_DIRS = \
-	$(PRODUCTION_SOURCES)/llist
-#	<Add here the folders that contain code under test>
-
-SRC_FILES = \
-#	$(PRODUCTION_SOURCES)/source_file.cpp
-#	<Add here the source file that is being tested>
-
-INCLUDE_DIRS +=\
-	$(PRODUCTION_SOURCES)/
+#
+#
+#
+
+#	When all source files in a folder are under tests, it is prefered to add the folder instead of adding individual source files.
+SRC_DIRS = \
+	$(PRODUCTION_SOURCES)/llist\
+	$(PRODUCTION_SOURCES)/char_stream_req\
+#	<Add here the folders that contain code under test>
+
+SRC_FILES = \
+#	$(PRODUCTION_SOURCES)/source_file.cpp
+#	<Add here the source file that is being tested>
+
+INCLUDE_DIRS +=\
+	$(PRODUCTION_SOURCES)/\
+	$(PRODUCTION_SOURCES)/char_stream_req\
 #	<Add here the folder that contains the headers. Note that the order is important!>

unit_tester/build/mk_common/utest_config_test_path.mk

@@ -1,19 +1,20 @@
-#
-#
-#
-
-INCLUDE_DIRS =\
-	.\
-	$(TEST_ROOT)/helpers/include\
-  	$(TEST_ROOT)/mocks/include\
-  	/usr/include\
-	$(CPPUTEST_HOME)/include\
-
-TEST_SRC_DIRS = \
-	$(TEST_ROOT)/helpers/src\
-	$(TEST_ROOT)/tests\
-	$(TEST_ROOT)/tests/llist_test\
-#	<Add here the folder that contains the tester source>	
-
-MOCKS_SRC_DIRS =\
+#
+#
+#
+
+INCLUDE_DIRS =\
+	.\
+	$(TEST_ROOT)/helpers/include\
+  	$(TEST_ROOT)/mocks/include\
+  	/usr/include\
+	$(CPPUTEST_HOME)/include\
+
+TEST_SRC_DIRS = \
+	$(TEST_ROOT)/helpers/src\
+	$(TEST_ROOT)/tests\
+	$(TEST_ROOT)/tests/llist_test\
+	$(TEST_ROOT)/tests/char_stream_req_test\
+#	<Add here the folder that contains the tester source>	
+
+MOCKS_SRC_DIRS =\
 	$(TEST_ROOT)/mocks/src\

unit_tester/tests/char_stream_req_test/char_stream_req_test.cpp

@@ -0,0 +1,98 @@
+/*
+ * char_stream_req_test.cpp
+ *
+ *  Created on: Nov 14, 2014
+ *      Author: edwardh
+ */
+
+#include "CppUTest/TestHarness.h"
+
+#include "char_stream_req.h"
+
+
+TEST_GROUP(char_stream_req)
+{
+    static const int bulk_size = 100000;
+
+    void setup()
+    {
+    }
+
+    void teardown()
+    {
+    }
+};
+
+TEST(char_stream_req, unique_input_alphanumeric)
+{
+
+    const char *cstream_in = "abc123";
+    const char *cstream_expected = "123abc";
+    char        cstream_out[bulk_size];
+
+    CharStreamReq csr;
+
+    for(char *ch_itr = (char*)cstream_in; (*ch_itr != '\0'); ++ch_itr)
+        csr.recv(*ch_itr);
+
+    csr.printRecvSorted(cstream_out, bulk_size);
+
+    STRCMP_EQUAL(cstream_expected, cstream_out);
+}
+
+TEST(char_stream_req, non_unique_input_alphanumeric)
+{
+
+    const char *cstream_in = "abbc13b213";
+    const char *cstream_expected = "11233abbbc";
+    char        cstream_out[bulk_size];
+
+    CharStreamReq csr;
+
+    for(char *ch_itr = (char*)cstream_in; (*ch_itr != '\0'); ++ch_itr)
+        csr.recv(*ch_itr);
+
+    csr.printRecvSorted(cstream_out, bulk_size);
+
+    STRCMP_EQUAL(cstream_expected, cstream_out);
+}
+
+/*
+ * Current implementation assumes that the output is sorted based on the
+ * ASCII table (For alphanumeric: Numbers, Upper chars and lastly Lower chars.
+ */
+TEST(char_stream_req, non_unique_input_alphanumeric_w_low_and_up_chars)
+{
+
+    const char *cstream_in = "abBc13Ab213";
+    const char *cstream_expected = "11233ABabbc";
+    char        cstream_out[bulk_size];
+
+    CharStreamReq csr;
+
+    for(char *ch_itr = (char*)cstream_in; (*ch_itr != '\0'); ++ch_itr)
+        csr.recv(*ch_itr);
+
+    csr.printRecvSorted(cstream_out, bulk_size);
+
+    STRCMP_EQUAL(cstream_expected, cstream_out);
+}
+
+TEST(char_stream_req, input_larger_than_outbuffer__output_only_4_chars)
+{
+
+    const char *cstream_in = "a1b3c2";
+    const char *cstream_expected = "123";
+
+    const int   small_bulk_size = 4;
+    char        cstream_out[small_bulk_size];
+
+    CharStreamReq csr;
+
+    for(char *ch_itr = (char*)cstream_in; (*ch_itr != '\0'); ++ch_itr)
+        csr.recv(*ch_itr);
+
+    csr.printRecvSorted(cstream_out, small_bulk_size);
+
+    STRCMP_EQUAL(cstream_expected, cstream_out);
+}