Move various files that don't need to be in basic/ to shared/

This doesn't have much effect on the final build, because we link libbasic.a
into libsystemd-shared.so, so in the end, all the object built from basic/
end up in libsystemd-shared. And when the static library is linked into binaries,
any objects that are included in it but are not used are trimmed. Hence, the
size of output artifacts doesn't change:

$ du -sb /var/tmp/inst*
54181861	/var/tmp/inst1    (old)
54207441	/var/tmp/inst1s   (old split-usr)
54182477	/var/tmp/inst2    (new)
54208041	/var/tmp/inst2s   (new split-usr)

(The negligible change in size is because libsystemd-shared.so is bigger
by a few hundred bytes. I guess it's because symbols are named differently
or something like that.)

The effect is on the build process, in particular partial builds. This change
effectively moves the requirements on some build steps toward the leaves of the
dependency tree. Two effects:
- when building items that do not depend on libsystemd-shared, we
  build less stuff for libbasic.a (which wouldn't be used anyway,
  so it's a net win).
- when building items that do depend on libshared, we reduce libbasic.a as a
  synchronization point, possibly allowing better parallelism.

Method:
1. copy list of .h files from src/basic/meson.build to /tmp/basic
2. $ for i in $(grep '.h$' /tmp/basic); do echo $i; git --no-pager grep "include \"$i\"" src/basic/ 'src/lib*' 'src/nss-*' 'src/journal/sd-journal.c' |grep -v "${i%.h}.c";echo ;done | less

1 files changed, 61 insertions, 0 deletions

diff --git a/src/shared/journal-importer.h b/src/shared/journal-importer.h
new file mode 100644
index 0000000000..53354b7c78
--- /dev/null
+++ b/src/shared/journal-importer.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#pragma once
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <sys/uio.h>
+
+#include "sd-id128.h"
+
+#include "time-util.h"
+
+/* Make sure not to make this smaller than the maximum coredump size.
+ * See JOURNAL_SIZE_MAX in coredump.c */
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+#define ENTRY_SIZE_MAX (1024*1024*770u)
+#define DATA_SIZE_MAX (1024*1024*768u)
+#else
+#define ENTRY_SIZE_MAX (1024*1024*13u)
+#define DATA_SIZE_MAX (1024*1024*11u)
+#endif
+#define LINE_CHUNK 8*1024u
+
+struct iovec_wrapper {
+        struct iovec *iovec;
+        size_t size_bytes;
+        size_t count;
+};
+
+size_t iovw_size(struct iovec_wrapper *iovw);
+
+typedef struct JournalImporter {
+        int fd;
+        bool passive_fd;
+        char *name;
+
+        char *buf;
+        size_t size;       /* total size of the buffer */
+        size_t offset;     /* offset to the beginning of live data in the buffer */
+        size_t scanned;    /* number of bytes since the beginning of data without a newline */
+        size_t filled;     /* total number of bytes in the buffer */
+
+        size_t field_len;  /* used for binary fields: the field name length */
+        size_t data_size;  /* and the size of the binary data chunk being processed */
+
+        struct iovec_wrapper iovw;
+
+        int state;
+        dual_timestamp ts;
+        sd_id128_t boot_id;
+} JournalImporter;
+
+void journal_importer_cleanup(JournalImporter *);
+int journal_importer_process_data(JournalImporter *);
+int journal_importer_push_data(JournalImporter *, const char *data, size_t size);
+void journal_importer_drop_iovw(JournalImporter *);
+bool journal_importer_eof(const JournalImporter *);
+
+static inline size_t journal_importer_bytes_remaining(const JournalImporter *imp) {
+        return imp->filled;
+}