[C] Optimize memory usage when printing JSON

.github/workflows/samples-c-libcurl-client.yaml

@@ -4,22 +4,31 @@ on:
   push:
     paths:
       - 'samples/client/petstore/c/**'
+      - 'samples/client/petstore/c-useJsonUnformatted/**'
   pull_request:
     paths:
       - 'samples/client/petstore/c/**'
+      - 'samples/client/petstore/c-useJsonUnformatted/**'
 
 jobs:
   build:
     name: Build c libcurl client
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sample:
+          - 'samples/client/petstore/c/'
+          - 'samples/client/petstore/c-useJsonUnformatted/'
+
     steps:
       - uses: actions/checkout@v4
       - name: Prepare
         run: |
           sudo apt-get update
           sudo apt-get install -y libssl-dev libcurl4-openssl-dev
       - name: Build
-        working-directory: "samples/client/petstore/c"
+        working-directory: ${{ matrix.sample }}
         run: |
           mkdir build
           cd build

bin/configs/c-useJsonUnformatted.yaml

@@ -0,0 +1,9 @@
+generatorName: c
+outputDir: samples/client/petstore/c-useJsonUnformatted
+inputSpec: modules/openapi-generator/src/test/resources/2_0/c/petstore.yaml
+templateDir: modules/openapi-generator/src/main/resources/C-libcurl
+additionalProperties:
+  useJsonUnformatted: true
+modelNameMappings:
+  another_model: MappedModel
+  another_property: mappedProperty

docs/generators/c.md

@@ -27,6 +27,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
 |sortModelPropertiesByRequiredFlag|Sort model properties to place required parameters before optional parameters.| |true|
 |sortParamsByRequiredFlag|Sort method arguments to place required parameters before optional parameters.| |true|
+|useJsonUnformatted|Use cJSON_PrintUnformatted instead of cJSON_Print when creating the JSON string.| |false|
 
 ## IMPORT MAPPING
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CLibcurlClientCodegen.java

@@ -39,6 +39,9 @@
 public class CLibcurlClientCodegen extends DefaultCodegen implements CodegenConfig {
     private final Logger LOGGER = LoggerFactory.getLogger(CLibcurlClientCodegen.class);
 
+    public static final String USE_JSON_UNFORMATTED = "useJsonUnformatted";
+    public static final String USE_JSON_UNFORMATTED_DESC = "Use cJSON_PrintUnformatted instead of cJSON_Print when creating the JSON string.";
+
     public static final String PROJECT_NAME = "projectName";
     protected String moduleName;
     protected String projectName;
@@ -47,6 +50,7 @@ public class CLibcurlClientCodegen extends DefaultCodegen implements CodegenConf
     protected String libFolder = "lib";
     protected String apiDocPath = "docs/";
     protected String modelDocPath = "docs/";
+    protected boolean useJsonUnformatted = false;
 
     protected static int emptyMethodNameCounter = 0;
 
@@ -306,6 +310,8 @@ public CLibcurlClientCodegen() {
         cliOptions.add(new CliOption(CodegenConstants.HIDE_GENERATION_TIMESTAMP, CodegenConstants.HIDE_GENERATION_TIMESTAMP_DESC).
                 defaultValue(Boolean.TRUE.toString()));
 
+        cliOptions.add(new CliOption(USE_JSON_UNFORMATTED, USE_JSON_UNFORMATTED_DESC).
+                defaultValue(Boolean.FALSE.toString()));
     }
 
     @Override
@@ -316,6 +322,15 @@ public void processOpts() {
             LOGGER.info("Environment variable C_POST_PROCESS_FILE not defined so the C code may not be properly formatted by uncrustify (0.66 or later) or other code formatter. To define it, try `export C_POST_PROCESS_FILE=\"/usr/local/bin/uncrustify --no-backup\" && export UNCRUSTIFY_CONFIG=/path/to/uncrustify-rules.cfg` (Linux/Mac). Note: replace /path/to with the location of uncrustify-rules.cfg");
         }
 
+        if (additionalProperties.containsKey(USE_JSON_UNFORMATTED)) {
+            useJsonUnformatted = Boolean.parseBoolean(additionalProperties.get(USE_JSON_UNFORMATTED).toString());
+        }
+        if (useJsonUnformatted) {
+            additionalProperties.put("cJSONPrint", "cJSON_PrintUnformatted");
+        } else {
+            additionalProperties.put("cJSONPrint", "cJSON_Print");
+        }
+
         // make api and model doc path available in mustache template
         additionalProperties.put("apiDocPath", apiDocPath);
         additionalProperties.put("modelDocPath", modelDocPath);

modules/openapi-generator/src/main/resources/C-libcurl/CMakeLists.txt.mustache

@@ -56,13 +56,13 @@ set(SRCS
     model/object.c
 {{#models}}
 {{#model}}
-    model/{{classname}}.c
+    model/{{classFilename}}.c
 {{/model}}
 {{/models}}
 {{#apiInfo}}
 {{#apis}}
 {{#operations}}
-    api/{{classname}}.c
+    api/{{classFilename}}.c
 {{/operations}}
 {{/apis}}
 {{/apiInfo}}
@@ -78,13 +78,13 @@ set(HDRS
     model/object.h
 {{#models}}
 {{#model}}
-    model/{{classname}}.h
+    model/{{classFilename}}.h
 {{/model}}
 {{/models}}
 {{#apiInfo}}
 {{#apis}}
 {{#operations}}
-    api/{{classname}}.h
+    api/{{classFilename}}.h
 {{/operations}}
 {{/apis}}
 {{/apiInfo}}

modules/openapi-generator/src/main/resources/C-libcurl/api-body.mustache

@@ -320,7 +320,7 @@ end:
             goto end;
         }
         cJSON_AddItemToArray(localVarSingleItemJSON_{{paramName}}, localVar_{{paramName}});
-        localVarBodyParameters = cJSON_Print(localVarItemJSON_{{paramName}});
+        localVarBodyParameters = {{{cJSONPrint}}}(localVarItemJSON_{{paramName}});
     }
     {{/isArray}}
     {{^isArray}}
@@ -329,7 +329,7 @@ end:
     {
         //string
         localVarSingleItemJSON_{{paramName}} = {{dataType}}_convertToJSON({{paramName}});
-        localVarBodyParameters = cJSON_Print(localVarSingleItemJSON_{{paramName}});
+        localVarBodyParameters = {{{cJSONPrint}}}(localVarSingleItemJSON_{{paramName}});
     }
     {{/isArray}}
     {{/bodyParam}}
@@ -368,7 +368,7 @@ end:
     cJSON *{{{paramName}}}VarJSON;
     list_t *elementToReturn = list_createList();
     cJSON_ArrayForEach({{{paramName}}}VarJSON, {{paramName}}localVarJSON){
-        keyValuePair_t *keyPair = keyValuePair_create(strdup({{{paramName}}}VarJSON->string), cJSON_Print({{{paramName}}}VarJSON));
+        keyValuePair_t *keyPair = keyValuePair_create(strdup({{{paramName}}}VarJSON->string), {{{cJSONPrint}}}({{{paramName}}}VarJSON));
         list_addElement(elementToReturn, keyPair);
     }
     cJSON_Delete({{paramName}}localVarJSON);
@@ -389,7 +389,7 @@ end:
         {
            // return 0;
         }
-        char *localVarJSONToChar = cJSON_Print({{{paramName}}}VarJSON);
+        char *localVarJSONToChar = {{{cJSONPrint}}}({{{paramName}}}VarJSON);
         list_addElement(elementToReturn , localVarJSONToChar);
     }