src/jobs: init

implement data structures and json unmarshalling

3 files changed, 260 insertions, 1 deletions

diff --git a/src/jobs.c b/src/jobs.c
new file mode 100644
index 0000000..7893632
--- /dev/null
+++ b/src/jobs.c
@@ -0,0 +1,178 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <cjson/cJSON.h>
+
+#include "jobs.h"
+#include "util.h"
+
+static int job_output_insert(struct job *j, char *name, char *store_path);
+
+int job_read(FILE *stream, struct job **job)
+{
+	int ret;
+	cJSON *root, *temp, *input_drvs, *array;
+	struct job *dep_job;
+	char *name = NULL;
+	char *out_name = NULL;
+	char *drv_path = NULL;
+
+	ret = json_streaming_read(stream, &root);
+	if (ret < 0)
+		return ret;
+
+	temp = cJSON_GetObjectItemCaseSensitive(root, "name");
+	if (!cJSON_IsString(temp)) {
+		ret = -EPERM;
+		goto out_free;
+	}
+	name = strdup(temp->valuestring);
+	if (name == NULL) {
+		ret = -EPERM;
+		goto out_free;
+	}
+
+	temp = cJSON_GetObjectItemCaseSensitive(root, "drvPath");
+	if (!cJSON_IsString(temp)) {
+		ret = -EPERM;
+		goto out_free;
+	}
+	drv_path = strdup(temp->valuestring);
+	if (drv_path == NULL) {
+		ret = -EPERM;
+		goto out_free;
+	}
+
+	ret = job_new(job, name, drv_path);
+	if (ret < 0)
+		goto out_free;
+
+	input_drvs = cJSON_GetObjectItemCaseSensitive(root, "inputDrvs");
+	for (temp = input_drvs; temp != NULL; temp = temp->next) {
+		array = cJSON_GetObjectItemCaseSensitive(temp, temp->string);
+		if (!cJSON_IsArray(array)) {
+			ret = -EPERM;
+			job_free(*job);
+			goto out_free;
+		}
+
+		drv_path = strdup(temp->string);
+		if (drv_path == NULL) {
+			ret = -EPERM;
+			job_free(*job);
+			goto out_free;
+		}
+
+		ret = job_new(&dep_job, NULL, drv_path);
+		if (ret < 0) {
+			ret = -EPERM;
+			job_free(*job);
+			goto out_free;
+		}
+
+		for (; array != NULL; array = array->next) {
+			out_name = strdup(array->string);
+			ret = job_output_insert(dep_job, out_name, NULL);
+			if (ret < 0) {
+				job_free(*job);
+				job_free(dep_job);
+				goto out_free;
+			}
+		}
+
+		LIST_INSERT_HEAD(&(*job)->deps, dep_job, dlist);
+		drv_path = NULL;
+	}
+
+out_free:
+	cJSON_Delete(root);
+
+	if (ret < 0) {
+		print_err("%s", "Invalid JSON");
+		free(name);
+		free(drv_path);
+	}
+	return ret;
+}
+
+void output_free(struct output *output)
+{
+	if (output == NULL)
+		return;
+
+	free(output->name);
+	free(output->store_path);
+
+	free(output);
+}
+
+void job_free(struct job *job)
+{
+	struct job *j;
+	struct output *o;
+
+	if (job == NULL)
+		return;
+
+	free(job->name);
+	free(job->drv_path);
+	free(job);
+	LIST_FOREACH (o, &job->outputs, dlist)
+		output_free(o);
+
+	LIST_FOREACH (j, &job->deps, dlist)
+		job_free(j);
+}
+
+static int job_output_insert(struct job *j, char *name, char *store_path)
+{
+	struct output *o;
+
+	o = malloc(sizeof(*o));
+	if (o == NULL) {
+		print_err("%s", strerror(errno));
+		return -errno;
+	}
+
+	o->name = name;
+	o->store_path = store_path;
+	LIST_INSERT_HEAD(&j->outputs, o, dlist);
+
+	return 0;
+}
+
+int job_new(struct job **j, char *name, char *drv_path)
+{
+	struct job *job;
+
+	job = malloc(sizeof(*job));
+	if (*j == NULL) {
+		print_err("%s", strerror(errno));
+		return -errno;
+	}
+
+	job->name = name;
+	job->drv_path = drv_path;
+	LIST_INIT(&job->deps);
+	LIST_INIT(&job->outputs);
+
+	*j = job;
+	return 0;
+}
+
+int jobs_init(FILE **stream)
+{
+	int ret;
+
+	/* TODO: proproperly handle args */
+	char *const args[] = {
+		"--flake",
+		"github:sinanmohd/evanix#packages.x86_64-linux.evanix",
+	};
+
+	/* the package is wrapProgram-ed with nix-eval-jobs  */
+	ret = vpopen(stream, "nix-eval-jobs", args);
+	return ret;
+}
diff --git a/src/meson.build b/src/meson.build
index d34718a..5fe292f 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -1,6 +1,10 @@
 e = executable(
 	'evanix',
-        'evanix.c',
+        [
+		'evanix.c',
+		'jobs.c',
+		'util.c',
+	],
 
 	include_directories: evanix_inc,
 	dependencies: cjson_dep,
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..001180e
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,77 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <cjson/cJSON.h>
+
+#include "util.h"
+
+int json_streaming_read(FILE *stream, cJSON **json)
+{
+	int ret;
+	size_t n;
+	char *line = NULL;
+
+	ret = getline(&line, &n, stream);
+	if (ret < 0) {
+		if (errno != 0) {
+			print_err("%s", strerror(errno));
+			return -errno;
+		}
+
+		return -EOF;
+	}
+
+	*json = cJSON_Parse(line);
+	free(line);
+	if (cJSON_IsInvalid(*json)) {
+		print_err("%s", "Invalid JSON");
+		return -EPERM;
+	}
+
+	return 0;
+}
+
+int vpopen(FILE **stream, const char *file, char *const argv[])
+{
+	int fd[2];
+	int ret;
+
+	ret = pipe(fd);
+	if (ret < 0) {
+		print_err("%s", strerror(errno));
+		return -errno;
+	}
+
+	ret = fork();
+	if (ret < 0) {
+		print_err("%s", strerror(errno));
+
+		close(fd[0]);
+		close(fd[1]);
+		return -errno;
+	} else if (ret > 0) {
+		close(fd[1]);
+		*stream = fdopen(fd[0], "r");
+		if (*stream == NULL) {
+			print_err("%s", strerror(errno));
+			return -errno;
+		}
+
+		return 0;
+	}
+
+	close(fd[0]);
+	ret = dup2(fd[1], STDOUT_FILENO);
+	if (ret < 0)
+		goto out_err;
+
+	execvp(file, argv);
+
+out_err:
+	close(fd[1]);
+	print_err("%s", strerror(errno));
+	exit(EXIT_FAILURE);
+}