filter: split filter functions into their own file

A first step for more interesting things.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/filter.c b/filter.c
new file mode 100644
index 0000000..f4ee9ac
--- /dev/null
+++ b/filter.c
@@ -0,0 +1,82 @@
+/* filter.c: filter framework functions
+ *
+ * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
+ *
+ * Licensed under GNU General Public License v2
+ *   (see COPYING for full license text)
+ */
+
+#include "cgit.h"
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+
+int cgit_open_filter(struct cgit_filter *filter)
+{
+        filter->old_stdout = chk_positive(dup(STDOUT_FILENO),
+                "Unable to duplicate STDOUT");
+        chk_zero(pipe(filter->pipe_fh), "Unable to create pipe to subprocess");
+        filter->pid = chk_non_negative(fork(), "Unable to create subprocess");
+        if (filter->pid == 0) {
+                close(filter->pipe_fh[1]);
+                chk_non_negative(dup2(filter->pipe_fh[0], STDIN_FILENO),
+                        "Unable to use pipe as STDIN");
+                execvp(filter->cmd, filter->argv);
+                die_errno("Unable to exec subprocess %s", filter->cmd);
+        }
+        close(filter->pipe_fh[0]);
+        chk_non_negative(dup2(filter->pipe_fh[1], STDOUT_FILENO),
+                "Unable to use pipe as STDOUT");
+        close(filter->pipe_fh[1]);
+        return 0;
+}
+
+
+int cgit_close_filter(struct cgit_filter *filter)
+{
+        int exit_status;
+
+        chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO),
+                "Unable to restore STDOUT");
+        close(filter->old_stdout);
+        if (filter->pid < 0)
+                return 0;
+        waitpid(filter->pid, &exit_status, 0);
+        if (WIFEXITED(exit_status) && !WEXITSTATUS(exit_status))
+                return 0;
+        die("Subprocess %s exited abnormally", filter->cmd);
+}
+
+struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
+{
+        struct cgit_filter *f;
+        int args_size = 0;
+        int extra_args;
+
+        if (!cmd || !cmd[0])
+                return NULL;
+
+        switch (filtertype) {
+                case SOURCE:
+                case ABOUT:
+                        extra_args = 1;
+                        break;
+
+                case COMMIT:
+                default:
+                        extra_args = 0;
+                        break;
+        }
+        
+        f = xmalloc(sizeof(struct cgit_filter));
+        memset(f, 0, sizeof(struct cgit_filter));
+
+        f->cmd = xstrdup(cmd);
+        args_size = (2 + extra_args) * sizeof(char *);
+        f->argv = xmalloc(args_size);
+        memset(f->argv, 0, args_size);
+        f->argv[0] = f->cmd;
+        return f;
+}