cache downloads and cleaning

8 files changed, 115 insertions, 72 deletions

diff --git a/snag/src/build_db.c b/snag/src/build_db.c
new file mode 100644
index 0000000..f2f4e01
--- /dev/null
+++ b/snag/src/build_db.c
@@ -0,0 +1,53 @@
+#include "build_db.h"
+#include "util.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <errno.h>
+
+#define PKG_BUILD_CMD "./scripts/run_pkg_build.sh"
+
+void package_run_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_BUILD_CMD, info->script_path, NULL };
+        char* envp[] = { NULL };
+        execve(PKG_BUILD_CMD, argv, envp);
+		// what are you still doing here?
+		die("CHILD - execve to %s failed: %s", PKG_BUILD_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");
+}
diff --git a/snag/src/build_db.h b/snag/src/build_db.h
new file mode 100644
index 0000000..ed57c43
--- /dev/null
+++ b/snag/src/build_db.h
@@ -0,0 +1,8 @@
+#ifndef BUILD_DB_H
+#define BUILD_DB_H
+
+#include "package.h"
+
+void package_run_install(const package_info_t* info);
+
+#endif
diff --git a/snag/src/download_db.c b/snag/src/download_db.c
index c1e2e1b..c355566 100644
--- a/snag/src/download_db.c
+++ b/snag/src/download_db.c
@@ -6,6 +6,7 @@
 #include <openssl/evp.h>
 #include <openssl/sha.h>
 #include <string.h>
+#include <unistd.h>
 #include <errno.h>
 
 // note: fixed location of download database for now
@@ -29,10 +30,22 @@ static size_t download_write_callback(char* ptr, size_t size, size_t nmemb, void
 	return written;
 }
 
-bool download_package(package_info_t* pkg) {
+bool package_get_download(package_info_t* pkg, package_download_t* download) {
+    memset(download, 0, sizeof(*download));
 
+	// construct path of download
+	char* download_path = vastrcat(download_db_path, "/", pkg->attrs.id, "-", pkg->attrs.version, ".tar.gz");
+
+	// return download if it already exists in database
+    if (access(download_path, F_OK) == 0) {
+		download->download_path = download_path;
+		return true;
+    } else {
+		print("Downloading %s\n", pkg->attrs.source_url);
+	}
+
+	// initialize curl if it isn't already
 	if (curl == NULL) {
-		// initialize curl if it isn't already
 		CURLcode result = curl_global_init(CURL_GLOBAL_ALL);
 		if (result != CURLE_OK) die("failed to initialize curl: %s", curl_easy_strerror(result));
 		curl = curl_easy_init(); // note(jqj): for now we reuse one easy curl object
@@ -43,8 +56,8 @@ bool download_package(package_info_t* pkg) {
 		/* curl_global_cleanup(); */
 	}
 
+	// initialize libcrypto context if it isn't already
 	if (mdctx == NULL) {
-		// initialize libcrypto context if it isn't already
 		mdctx = EVP_MD_CTX_new();
 		md = EVP_sha256();
 
@@ -59,7 +72,6 @@ bool download_package(package_info_t* pkg) {
 	// note(jqj): extension is fixed to tar gz until the switch out download
 	//            attrs for the swenu api download command which will specify
 	//            more information
-	char* download_path = vastrcat(download_db_path, "/", pkg->attrs.id, "-", pkg->attrs.version, ".tar.gz");
 	FILE* download_file = fopen(download_path, "wb");
 	if (download_file == NULL) die("failed open download file for writing (%s): %s", download_path, strerror(errno));
 
@@ -73,7 +85,7 @@ bool download_package(package_info_t* pkg) {
     if(result != CURLE_OK) {
 		// todo(jqj): handle better, maybe try again
 		print("failed to download package with curl: %s", curl_easy_strerror(result));
-		return false;
+		goto fail;
 	}
 
 	// get sha256 hash
@@ -88,20 +100,25 @@ bool download_package(package_info_t* pkg) {
     }
 	hash_hex[SHA256_DIGEST_LENGTH * 2] = '\0';
 
+	// todo(jqj): collapse codepath and delete download if it doesn't match checksum
+
 	// confirm that hash matches checksum
 	if (pkg->attrs.source_checksum != NULL) {
 		if (strcmp(pkg->attrs.source_checksum, hash_hex) == 0) {
-			print("checksum verified for %s: %s\n", pkg->attrs.id, hash_hex);
+			print("checksum verified for download: %s\n", hash_hex);
+			download->download_path = download_path;
 			return true;
 		} else {
-			print("FAIL: bad checksum for %s: %s\n", pkg->attrs.id, hash_hex);
-			return false;
+			print("FAIL: bad checksum for download: %s\n", hash_hex);
+			goto fail;
 		}
 	} else {
 		// todo(jqj): not sure if we will allow packages without hashes yet
 		print("WARNING: could not verify checksum for %s download because none was provided\n", pkg->attrs.id);
-		return true;
+		goto fail;
 	}
 
-	return true;
+ fail:
+	free(download_path);
+	return false;
 }
diff --git a/snag/src/download_db.h b/snag/src/download_db.h
index fbf7b03..0f6e181 100644
--- a/snag/src/download_db.h
+++ b/snag/src/download_db.h
@@ -5,6 +5,10 @@
 
 #include "package.h"
 
-bool download_package(package_info_t* pkg);
+typedef struct {
+	char* download_path;
+} package_download_t;
+
+bool package_get_download(package_info_t* pkg, package_download_t* download);
 
 #endif
diff --git a/snag/src/main.c b/snag/src/main.c
index 0813032..921c31a 100644
--- a/snag/src/main.c
+++ b/snag/src/main.c
@@ -2,6 +2,7 @@
 
 #include "util.h"
 #include "package_db.h"
+#include "build_db.h"
 #include "download_db.h"
 
 int cmd_install(char* cmd_name, ArgParser* parser);
@@ -43,10 +44,14 @@ int cmd_install(char* cmd_name, ArgParser* parser) {
 		char* pkgid = ap_get_arg_at_index(parser, i);
 		package_info_t info;
 		if (load_package_info(pkgid, &info)) {
-			print("Downloading '%s'\n", info.attrs.source_url);
-			download_package(&info);
 			print("Installing %s - %s\n", info.attrs.name, info.attrs.desc);
-			run_package_install(&info);
+
+			// download or retrieve package download
+			package_download_t download;
+			package_get_download(&info, &download);
+
+			// run the package install
+			package_run_install(&info);
 		}
 	}
 
diff --git a/snag/src/package.h b/snag/src/package.h
index b848ce6..bdbf0cb 100644
--- a/snag/src/package.h
+++ b/snag/src/package.h
@@ -1,21 +1,21 @@
 #ifndef PACKAGE_H
 #define PACKAGE_H
 
+// this struct is the "handle" of a package to be passed into other package
+// functions
 typedef struct {
-	char* id;
-    char* name;
-    char* desc;
-    char* webpage;
-    char* license;
-    char* version;
-	char* source_url;
-	char* source_checksum;
-    char buffer[4069];
-} package_attrs_t;
-
-typedef struct {
-    char* script_path;
-    package_attrs_t attrs;
+	char* script_path;
+	struct {
+		char buffer[4069];
+		char* id;
+		char* name;
+		char* desc;
+		char* webpage;
+		char* license;
+		char* version;
+		char* source_url;
+		char* source_checksum;
+	} attrs;
 } package_info_t;
 
 #endif
diff --git a/snag/src/package_db.c b/snag/src/package_db.c
index 04705e4..e0d7e8a 100644
--- a/snag/src/package_db.c
+++ b/snag/src/package_db.c
@@ -9,7 +9,6 @@
 #include <errno.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[] = "./var/snag/packages";
@@ -117,45 +116,3 @@ bool load_package_info(char* pkgid, package_info_t* info) {
 
 	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");
-}
diff --git a/snag/src/package_db.h b/snag/src/package_db.h
index 17ff58d..52dad2b 100644
--- a/snag/src/package_db.h
+++ b/snag/src/package_db.h
@@ -9,6 +9,5 @@
 // excessive validation, so this should be fine when loading lots of package
 // data
 bool load_package_info(char* pkgid, package_info_t* info);
-void run_package_install(const package_info_t* info);
 
 #endif