clean up

1 files changed, 157 insertions, 0 deletions

diff --git a/snag/src/pkg_db.c b/snag/src/pkg_db.c
new file mode 100644
index 0000000..c35e47b
--- /dev/null
+++ b/snag/src/pkg_db.c
@@ -0,0 +1,157 @@
+#include "pkg_db.h"
+#include "util.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/wait.h>
+
+#define PKG_INFO_CMD "./scripts/get_pkg_attrs.sh"
+#define PKG_INST_CMD "./scripts/run_pkg_install.sh"
+
+// note: fixed location of package database for now
+const char pkg_db[] = "../packages";
+const size_t pkg_db_len = sizeof(pkg_db) - 1;
+
+bool load_package_info(char* pkgid, package_info_t* info) {
+
+    memset(info, 0, sizeof(*info));
+    size_t pkgid_len = strlen(pkgid);
+
+	// construct package description directory path and ensure it exists
+    // pkg_dir = "pkg_db/pkgid"
+	size_t pkg_dir_len = pkg_db_len + pkgid_len + 1;
+	char* pkg_dir = emalloc(pkg_dir_len + 1, "pkg_dir");
+	{
+		memcpy(pkg_dir, pkg_db, pkg_db_len);
+		pkg_dir[pkg_db_len] = '/';
+		memcpy(pkg_dir + pkg_db_len + 1, pkgid, pkgid_len);
+		pkg_dir[pkg_dir_len] = '\0';
+		if (access(pkg_dir, F_OK) != 0) {
+			print("Package '%s' not found\n", pkgid);
+			free(pkg_dir);
+			return false;
+		}
+	}
+
+	// construct package description script path and ensure it exists
+	// script_path = "pkg_dir/pkgid.sh"
+	size_t script_path_len = pkg_dir_len + pkgid_len + 4;
+	info->script_path = emalloc(script_path_len + 1, "info->script_path");
+	{
+		memcpy(info->script_path, pkg_dir, pkg_dir_len);
+		info->script_path[pkg_dir_len] = '/';
+		memcpy(&info->script_path[pkg_dir_len + 1], pkgid, pkgid_len);
+		memcpy(&info->script_path[script_path_len - 3], ".sh", 3);
+		info->script_path[script_path_len] = '\0';
+		free(pkg_dir);
+		if (access(info->script_path, F_OK) != 0) {
+			print("Package '%s' broken, doesn't have description script\n", pkgid);
+			free(info->script_path);
+			return false;
+		}
+	}
+
+	// PIPE and FORK to run pkg attrs script
+    int pipefds[2] = {0};
+    if (pipe(pipefds) < 0) die("failed to pipe: %s", strerror(errno));
+    pid_t pid = fork();
+    if (pid < 0) die("failed to fork: %s", strerror(errno));
+
+    if (pid == 0) {
+		// child proc
+		// connect my stdout to the pipe
+        close(pipefds[0]);
+        dup2(pipefds[1], STDOUT_FILENO);
+        close(pipefds[1]);
+		// exec into get attr script
+        char* argv[] = { PKG_INFO_CMD, info->script_path, NULL };
+        char* envp[] = { NULL };
+        execve(PKG_INFO_CMD, argv, envp);
+		// what are you still doing here?
+		die("CHILD - execve to %s failed: %s", PKG_INFO_CMD, strerror(errno));
+    } else {
+		// parent proc, close write end of pipe
+		close(pipefds[1]);
+	}
+
+	// wait for child to finish
+    int wstatus;
+    if (waitpid(pid, &wstatus, 0) < 0) die("waitpid failed: %s", strerror(errno));
+	if (WEXITSTATUS(wstatus) != 0) die("the child failed to execute get_pkg_attr script");
+
+	// read all bytes from pipe into attr buffer
+    ssize_t bytes_read = read(pipefds[0], info->attrs.buffer, sizeof(info->attrs.buffer));
+    if (bytes_read < 0) die("failed to read from pipe: %s", strerror(errno));
+	close(pipefds[0]);
+
+	// read attributes from attr buffer
+	// attribute format: type (char), data value (null terminated str)
+	// todo(jqj): switch over to dynamically allocated buffer
+    for (int i = 0; i < bytes_read;) {
+        char atype = info->attrs.buffer[i];
+        i++;
+        switch (atype) {
+        case 'i':
+            info->attrs.id = &info->attrs.buffer[i]; break;
+        case 'n':
+            info->attrs.name = &info->attrs.buffer[i]; break;
+        case 'd':
+            info->attrs.desc = &info->attrs.buffer[i]; break;
+		case 'w':
+			info->attrs.webpage = &info->attrs.buffer[i]; break;
+		case 'l':
+			info->attrs.license = &info->attrs.buffer[i]; break;
+		case 'v':
+			info->attrs.version = &info->attrs.buffer[i]; break;
+        }
+        for(;info->attrs.buffer[i] && i < bytes_read; i++);
+        i++;
+    }
+
+	return true;
+}
+
+void run_package_install(const package_info_t* info) {
+
+	// PIPE and FORK to run install script
+    int pipefds[2] = {0};
+    if (pipe(pipefds) < 0) die("failed to pipe: %s", strerror(errno));
+    pid_t pid = fork();
+    if (pid < 0) die("failed to fork: %s", strerror(errno));
+
+    if (pid == 0) {
+		// child proc
+		// connect my stdout and stderr to the pipe
+        close(pipefds[0]);
+        dup2(pipefds[1], STDOUT_FILENO);
+        dup2(pipefds[1], STDERR_FILENO);
+        close(pipefds[1]);
+		// exec into install script
+        char* argv[] = { PKG_INST_CMD, info->script_path, NULL };
+        char* envp[] = { NULL };
+        execve(PKG_INST_CMD, argv, envp);
+		// what are you still doing here?
+		die("CHILD - execve to %s failed: %s", PKG_INST_CMD, strerror(errno));
+    } else {
+		// parent proc, close write end of pipe
+		close(pipefds[1]);
+	}
+
+	// read from the pipe until EOF
+	char buf[4096];
+	ssize_t bytes_read = 0;
+    while ((bytes_read = read(pipefds[0], buf, sizeof(buf))) > 0) {
+		// print build out, can log and stuff in future
+		printf("%.*s", (int)bytes_read, buf);
+	}
+    if (bytes_read < 0) die("failed to read from pipe: %s", strerror(errno));
+	close(pipefds[0]);
+
+	// reap the child to finish
+    int wstatus;
+    if (waitpid(pid, &wstatus, 0) < 0) die("waitpid failed: %s", strerror(errno));
+	if (WEXITSTATUS(wstatus) != 0) die("the child failed to execute install script");
+}