TEST(externalSort, testCorrectSorting) {
int input, output, error;
if((input = open(inputfile.c_str(), O_RDONLY)) < 0) {
std::cerr << "cannot open input file: " << strerror(errno) << std::endl;
return;
}
uint64_t input_filesize = fsize(inputfile);
if((output = open(outputfile.c_str(), O_CREAT|O_TRUNC|O_WRONLY, S_IRUSR|S_IWUSR)) < 0) {
std::cerr << "cannot open output file: " << strerror(errno) << std::endl;
return;
} else if((error = posix_fallocate(output, 0, input_filesize))) {
std::cout << "error: " << strerror(error) << std::endl;
exit(1);
}
externalSort(input, input_filesize / sizeof(uint64_t) , output, memoryBuffer);
close(input);
close(output);
std::cout << "starting to check output" << std::endl;
if((output = open(outputfile.c_str(), O_RDONLY)) < 0) {
std::cerr << "cannot open output file for checking: " << strerror(errno) << std::endl;
return;
}
uint64_t number = 0, lastnumber = 0;
while(read(output, &number, sizeof(uint64_t)) > 0) {
EXPECT_GE(number, lastnumber);
lastnumber = number;
}
close(output);
}
// Driver program to test above functions
int main()
{
int N = 3; // Number of machines
// an array of pointers storing the head nodes of the linked lists
ListNode *array[N];
// Create a Linked List 30->40->50 for first machine
array[0] = NULL;
push (&array[0], 50);
push (&array[0], 40);
push (&array[0], 30);
// Create a Linked List 35->45 for second machine
array[1] = NULL;
push (&array[1], 45);
push (&array[1], 35);
// Create Linked List 10->60->70->80 for third machine
array[2] = NULL;
push (&array[2], 100);
push (&array[2], 80);
push (&array[2], 70);
push (&array[2], 60);
push (&array[2], 10);
// Sort all elements
externalSort( array, N );
return 0;
}
/* Compress the custkey in orders. */
bool pageManage::compressCustkey() {
/* External sort. */
if (!externalSort())
return false;
/* Open the relevant files. */
FILE* cfileAfterSort = fopen(PATH_OF_CUSTKEY_AFTER_SORT, "rb"),
*cfileAfterCompress = fopen(PATH_OF_CUSTKEY_AFTER_COMPRESS, "wb");
if (!cfileAfterSort || !cfileAfterCompress)
return false;
int ckeyAfterSort[MAX_ITEM], count = 0, length = 1, pre_ckey = -1;
item ckeyAfterCompress[MAX_ITEM];
/* Compress custkey sort. */
while(!feof(cfileAfterSort)) {
int num = fread(ckeyAfterSort, sizeof(int), MAX_ITEM, cfileAfterSort);
for (int i = 0; i < num; ++i) {
if (ckeyAfterSort[i] == pre_ckey) {
++length;
} else if (pre_ckey != -1) {
if (count == MAX_ITEM) {
fwrite(ckeyAfterCompress, sizeof(item), count, cfileAfterCompress);
count = 0;
}
ckeyAfterCompress[count++] = item(pre_ckey, length);
length = 1;
}
pre_ckey = ckeyAfterSort[i];
}
}
if (count != 0)
fwrite(ckeyAfterCompress, sizeof(item), count, cfileAfterCompress);
item last_item(pre_ckey, length);
fwrite(&last_item, sizeof(item), 1, cfileAfterCompress);
/* Close the relevant files and remove the temporary files. */
fclose(cfileAfterSort);
fclose(cfileAfterCompress);
remove(PATH_OF_CUSTKEY_AFTER_SORT);
return true;
}
int main(int argc, char* argv[]) {
if (argc < 4) {
std::cerr << "usage: " << argv[0] << " <inputFile> <outputFile> <memoryBufferInMB>" << std::endl;
return -1;
}
unsigned bufferSize = atoi(argv[3])*1024;
if (bufferSize < 1024) {
std::cerr << "invalid memory buffer size (min. 1MB): " << argv[3] << std::endl;
return -1;
}
int fi, fo;
if ((fi = open(argv[1], O_RDONLY)) < 0) {
std::cerr << "cannot open input file '" << argv[1] << "': " << strerror(errno) << std::endl;
return -1;
}
struct stat st;
if(fstat(fi, &st) < 0){
std::cerr << "fstat for file '" << argv[1] << "' failed: " << strerror(errno) << std::endl;
return -1;
}
long long fileSize = st.st_size;
if(fileSize%sizeof(uint64_t) != 0){
std::cerr << "file size has to be a multiple of 64 Bit" << std::endl;
return -1;
}
if ((fo = open(argv[2], O_CREAT|O_TRUNC|O_WRONLY, S_IRUSR|S_IWUSR)) < 0) {
std::cerr << "cannot open output file '" << argv[2] << "': " << strerror(errno) << std::endl;
return -1;
}
externalSort(fi, fileSize/sizeof(uint64_t), fo, bufferSize);
close(fi);
close(fo);
return 0;
}