Call chdb via dlopen

examples/chdbDlopen.c

@@ -0,0 +1,111 @@
+#include <dlfcn.h> // Include for dynamic loading
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// Assuming chdb.h defines the structure and functions we need
+#include "chdb.h"
+
+int main()
+{
+    void * handle;
+    struct local_result * (*query_stable)(int, char **);
+    void (*free_result)(struct local_result *);
+
+    // Load the libchdb.so from the parent directory
+    handle = dlopen("../libchdb.so", RTLD_LAZY);
+    if (!handle)
+    {
+        fprintf(stderr, "Error loading libchdb.so: %s\n", dlerror());
+        exit(1);
+    }
+
+    // Get the query_stable function
+    *(void **)(&query_stable) = dlsym(handle, "query_stable");
+    if (!query_stable)
+    {
+        fprintf(stderr, "Could not find query_stable: %s\n", dlerror());
+        dlclose(handle);
+        exit(1);
+    }
+
+    // Get the free_result function
+    *(void **)(&free_result) = dlsym(handle, "free_result");
+    if (!free_result)
+    {
+        fprintf(stderr, "Could not find free_result: %s\n", dlerror());
+        dlclose(handle);
+        exit(1);
+    }
+
+    // Define query parameters
+    const char * output_format = "CSV";
+    const char * queryStr = "SELECT 'Hello libchdb.so from chdbDlopen'"; // Replace with your query string
+    const char * path = ""; // Replace with the path if needed
+    const char * udfPath = ""; // Replace with the UDF path if needed
+
+    // Prepare the argument array
+    char * argv[10]; // Adjust array size as needed
+    int argc = 0;
+    argv[argc++] = "clickhouse";
+    argv[argc++] = "--multiquery";
+
+    // Add parameters based on the output format
+    if (strcmp(output_format, "Debug") == 0 || strcmp(output_format, "debug") == 0)
+    {
+        argv[argc++] = "--verbose";
+        argv[argc++] = "--log-level=trace";
+        argv[argc++] = "--output-format=CSV";
+    }
+    else
+    {
+        char output_format_arg[50];
+        sprintf(output_format_arg, "--output-format=%s", output_format);
+        argv[argc++] = strdup(output_format_arg); // Note: Memory allocated by strdup needs to be freed
+    }
+
+    // If path is not empty, add corresponding parameter
+    if (path && *path)
+    {
+        char path_arg[100];
+        sprintf(path_arg, "--path=%s", path);
+        argv[argc++] = path_arg;
+    }
+
+    // Add query string
+    char query_arg[1000]; // Adjust size to fit actual query string length
+    sprintf(query_arg, "--query=%s", queryStr);
+    argv[argc++] = query_arg;
+
+    // If udfPath is not empty, add corresponding parameters
+    if (udfPath && *udfPath)
+    {
+        argv[argc++] = "--";
+        char udfPath_arg1[200]; // Adjust size to fit actual query string length
+        sprintf(udfPath_arg1, "--user_scripts_path=%s", udfPath);
+        argv[argc++] = udfPath_arg1; // Memory allocated by strdup needs to be freed
+
+        char udfPath_arg2[200]; // Adjust size to fit actual query string length
+        sprintf(udfPath_arg2, "--user_defined_executable_functions_config=%s/*.xml", udfPath);
+        argv[argc++] = udfPath_arg2; // Memory allocated by strdup needs to be freed
+    }
+
+    // Call the query_stable function
+    struct local_result * result = query_stable(argc, argv);
+
+    // Print results (assuming it's a string type, adjust according to actual data type)
+    if (result)
+    {
+        printf("Query Result: %s\n", result->buf);
+        printf("Elapsed Time: %fs\n", result->elapsed);
+        printf("Rows Read: %llu\n", (unsigned long long)result->rows_read);
+        printf("Bytes Read: %llu\n", (unsigned long long)result->bytes_read);
+
+        // Free the result
+        free_result(result);
+    }
+
+    // Remember to close the library handle at the end
+    dlclose(handle);
+    return 0;
+}

examples/chdbStub.c

@@ -65,8 +65,8 @@ int main()
     {
         printf("Query Result: %s\n", result->buf);
         printf("Elapsed Time: %fs\n", result->elapsed);
-        printf("Rows Read: %llu\n", result->rows_read);
-        printf("Bytes Read: %llu\n", result->bytes_read);
+        printf("Rows Read: %llu\n", (unsigned long long)result->rows_read);
+        printf("Bytes Read: %llu\n", (unsigned long long)result->bytes_read);
 
         // Free the result
         free_result(result);

examples/runStubDlopen.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+set -e
+
+# check current os type, and make ldd command
+if [ "$(uname)" == "Darwin" ]; then
+    LDD="otool -L"
+    LIB_PATH="DYLD_LIBRARY_PATH"
+elif [ "$(uname)" == "Linux" ]; then
+    LDD="ldd"
+    LIB_PATH="LD_LIBRARY_PATH"
+else
+    echo "OS not supported"
+    exit 1
+fi
+
+# cd to the directory of this script
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+cd $DIR
+
+echo "Compile and link"
+clang chdbDlopen.c -o chdbDlopen -I../programs/local/ -ldl
+
+export ${LIB_PATH}=..
+${LDD} chdbDlopen
+
+echo "Run it:"
+./chdbDlopen