[PATCH 6/6] Add SVN dump parser

[Ramkumar Ramachandra <artagnon@gmail.com>]

From: David Barr <david.barr@cordelta.com>

svndump parses data that is in SVN dumpfile format produced by
`svnadmin dump` with the help of line_buffer, and uses repo_tree and
fast_export to emit a git fast-import stream.

Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
---
 vcs-svn/svndump.c |  298 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 vcs-svn/svndump.h |    7 ++
 2 files changed, 305 insertions(+), 0 deletions(-)
 create mode 100644 vcs-svn/svndump.c
 create mode 100644 vcs-svn/svndump.h

diff --git a/vcs-svn/svndump.c b/vcs-svn/svndump.c
new file mode 100644
index 0000000..92c15d7
--- /dev/null
+++ b/vcs-svn/svndump.c
@@ -0,0 +1,298 @@
+/*
+ * Parse and rearrange a svnadmin dump.
+ * Create the dump with:
+ * svnadmin dump --incremental -r<startrev>:<endrev> <repository> >outfile
+ *
+ * Licensed under a two-clause BSD-style license.
+ * See LICENSE for details.
+ */
+
+#include "cache.h"
+#include "git-compat-util.h"
+
+#include "repo_tree.h"
+#include "fast_export.h"
+#include "line_buffer.h"
+#include "obj_pool.h"
+#include "string_pool.h"
+
+#define NODEACT_REPLACE 4
+#define NODEACT_DELETE 3
+#define NODEACT_ADD 2
+#define NODEACT_CHANGE 1
+#define NODEACT_UNKNOWN 0
+
+#define DUMP_CTX 0
+#define REV_CTX  1
+#define NODE_CTX 2
+
+#define LENGTH_UNKNOWN (~0)
+#define DATE_RFC2822_LEN 31
+
+/* Create memory pool for log messages */
+obj_pool_gen(log, char, 4096);
+
+static char* log_copy(uint32_t length, char *log)
+{
+	char *buffer;
+	log_free(log_pool.size);
+	buffer = log_pointer(log_alloc(length));
+	strncpy(buffer, log, length);
+	return buffer;
+}
+
+static struct {
+	uint32_t action, propLength, textLength, srcRev, srcMode, mark, type;
+	uint32_t src[REPO_MAX_PATH_DEPTH], dst[REPO_MAX_PATH_DEPTH];
+} node_ctx;
+
+static struct {
+	uint32_t revision, author;
+	unsigned long timestamp;
+	char *log;
+} rev_ctx;
+
+static struct {
+	uint32_t uuid, url;
+} dump_ctx;
+
+static struct {
+	uint32_t svn_log, svn_author, svn_date, svn_executable, svn_special, uuid,
+		revision_number, node_path, node_kind, node_action,
+		node_copyfrom_path, node_copyfrom_rev, text_content_length,
+		prop_content_length, content_length;
+} keys;
+
+static void reset_node_ctx(char *fname)
+{
+	node_ctx.type = 0;
+	node_ctx.action = NODEACT_UNKNOWN;
+	node_ctx.propLength = LENGTH_UNKNOWN;
+	node_ctx.textLength = LENGTH_UNKNOWN;
+	node_ctx.src[0] = ~0;
+	node_ctx.srcRev = 0;
+	node_ctx.srcMode = 0;
+	pool_tok_seq(REPO_MAX_PATH_DEPTH, node_ctx.dst, "/", fname);
+	node_ctx.mark = 0;
+}
+
+static void reset_rev_ctx(uint32_t revision)
+{
+	rev_ctx.revision = revision;
+	rev_ctx.timestamp = "";
+	rev_ctx.log = NULL;
+	rev_ctx.author = ~0;
+}
+
+static void reset_dump_ctx(uint32_t url)
+{
+	dump_ctx.url = url;
+	dump_ctx.uuid = ~0;
+}
+
+static void init_keys(void)
+{
+	keys.svn_log = pool_intern("svn:log");
+	keys.svn_author = pool_intern("svn:author");
+	keys.svn_date = pool_intern("svn:date");
+	keys.svn_executable = pool_intern("svn:executable");
+	keys.svn_special = pool_intern("svn:special");
+	keys.uuid = pool_intern("UUID");
+	keys.revision_number = pool_intern("Revision-number");
+	keys.node_path = pool_intern("Node-path");
+	keys.node_kind = pool_intern("Node-kind");
+	keys.node_action = pool_intern("Node-action");
+	keys.node_copyfrom_path = pool_intern("Node-copyfrom-path");
+	keys.node_copyfrom_rev = pool_intern("Node-copyfrom-rev");
+	keys.text_content_length = pool_intern("Text-content-length");
+	keys.prop_content_length = pool_intern("Prop-content-length");
+	keys.content_length = pool_intern("Content-length");
+}
+
+static void read_props(void)
+{
+	uint32_t len;
+	uint32_t key = ~0;
+	char buffer[27];
+	char *val = NULL;
+	char *t;
+	while ((t = buffer_read_line()) && strcmp(t, "PROPS-END")) {
+		if (!strncmp(t, "K ", 2)) {
+			len = atoi(&t[2]);
+			key = pool_intern(buffer_read_string(len));
+			buffer_read_line();
+		} else if (!strncmp(t, "V ", 2)) {
+			len = atoi(&t[2]);
+			val = buffer_read_string(len);
+			if (key == keys.svn_log) {
+				/* Value length excludes terminating nul. */
+				rev_ctx.log = log_copy(len + 1, val);
+			} else if (key == keys.svn_author) {
+				rev_ctx.author = pool_intern(val);
+			} else if (key == keys.svn_date) {
+				if (parse_date(val, buffer, sizeof(buffer)) > 0)
+					rev_ctx.timestamp = strtoul(buffer, NULL, 0);
+				else
+					fprintf(stderr, "Invalid timestamp: %s", val);
+			} else if (key == keys.svn_executable) {
+				node_ctx.type = REPO_MODE_EXE;
+			} else if (key == keys.svn_special) {
+				node_ctx.type = REPO_MODE_LNK;
+			}
+			key = ~0;
+			buffer_read_line();
+		}
+	}
+}
+
+static void handle_node(void)
+{
+	if (node_ctx.propLength != LENGTH_UNKNOWN && node_ctx.propLength) {
+		read_props();
+	}
+
+	if (node_ctx.srcRev) {
+		node_ctx.srcMode = repo_copy(node_ctx.srcRev, node_ctx.src, node_ctx.dst);
+	}
+
+	if (node_ctx.textLength != LENGTH_UNKNOWN &&
+		node_ctx.type != REPO_MODE_DIR) {
+		node_ctx.mark = next_blob_mark();
+	}
+
+	if (node_ctx.action == NODEACT_DELETE) {
+		repo_delete(node_ctx.dst);
+	} else if (node_ctx.action == NODEACT_CHANGE ||
+			   node_ctx.action == NODEACT_REPLACE) {
+		if (node_ctx.action == NODEACT_REPLACE &&
+			node_ctx.type == REPO_MODE_DIR) {
+			repo_replace(node_ctx.dst, node_ctx.mark);
+		} else if (node_ctx.propLength != LENGTH_UNKNOWN ) {
+			repo_modify(node_ctx.dst, node_ctx.type, node_ctx.mark);
+		} else if (node_ctx.textLength != LENGTH_UNKNOWN) {
+			node_ctx.srcMode = repo_replace(node_ctx.dst, node_ctx.mark);
+		}
+	} else if (node_ctx.action == NODEACT_ADD) {
+		if (node_ctx.srcRev &&
+			node_ctx.propLength != LENGTH_UNKNOWN) {
+			repo_modify(node_ctx.dst, node_ctx.type, node_ctx.mark);
+		} else if (node_ctx.srcRev &&
+			node_ctx.textLength != LENGTH_UNKNOWN) {
+			node_ctx.srcMode = repo_replace(node_ctx.dst, node_ctx.mark);
+		} else if ((node_ctx.type == REPO_MODE_DIR && !node_ctx.srcRev) ||
+				   node_ctx.textLength != LENGTH_UNKNOWN){
+			repo_add(node_ctx.dst, node_ctx.type, node_ctx.mark);
+		}
+	}
+
+	if (node_ctx.propLength == LENGTH_UNKNOWN && node_ctx.srcMode) {
+		node_ctx.type = node_ctx.srcMode;
+	}
+
+	if (node_ctx.mark) {
+		fast_export_blob(node_ctx.type, node_ctx.mark, node_ctx.textLength);
+	} else if (node_ctx.textLength != LENGTH_UNKNOWN) {
+		buffer_skip_bytes(node_ctx.textLength);
+	}
+}
+
+static void handle_revision(void)
+{
+	if (rev_ctx.revision)
+		repo_commit(rev_ctx.revision, rev_ctx.author, rev_ctx.log,
+			dump_ctx.uuid, dump_ctx.url, rev_ctx.timestamp);
+}
+
+void svndump_read(uint32_t url)
+{
+	char *val;
+	char *t;
+	uint32_t active_ctx = DUMP_CTX;
+	uint32_t len;
+	uint32_t key;
+
+	reset_dump_ctx(url);
+	while ((t = buffer_read_line())) {
+		val = strstr(t, ": ");
+		if (!val) continue;
+		*val++ = '\0';
+		*val++ = '\0';
+		key = pool_intern(t);
+
+		if(key == keys.uuid) {
+			dump_ctx.uuid = pool_intern(val);
+		} else if (key == keys.revision_number) {
+			if (active_ctx == NODE_CTX) handle_node();
+			if (active_ctx != DUMP_CTX) handle_revision();
+			active_ctx = REV_CTX;
+			reset_rev_ctx(atoi(val));
+		} else if (key == keys.node_path) {
+			if (active_ctx == NODE_CTX)
+				handle_node();
+			active_ctx = NODE_CTX;
+			reset_node_ctx(val);
+		} else if (key == keys.node_kind) {
+			if (!strcmp(val, "dir")) {
+				node_ctx.type = REPO_MODE_DIR;
+			} else if (!strcmp(val, "file")) {
+				node_ctx.type = REPO_MODE_BLB;
+			} else {
+				fprintf(stderr, "Unknown node-kind: %s\n", val);
+			}
+		} else if (key == keys.node_action) {
+			if (!strcmp(val, "delete")) {
+				node_ctx.action = NODEACT_DELETE;
+			} else if (!strcmp(val, "add")) {
+				node_ctx.action = NODEACT_ADD;
+			} else if (!strcmp(val, "change")) {
+				node_ctx.action = NODEACT_CHANGE;
+			} else if (!strcmp(val, "replace")) {
+				node_ctx.action = NODEACT_REPLACE;
+			} else {
+				fprintf(stderr, "Unknown node-action: %s\n", val);
+				node_ctx.action = NODEACT_UNKNOWN;
+			}
+		} else if (key == keys.node_copyfrom_path) {
+			pool_tok_seq(REPO_MAX_PATH_DEPTH, node_ctx.src, "/", val);
+		} else if (key == keys.node_copyfrom_rev) {
+			node_ctx.srcRev = atoi(val);
+		} else if (key == keys.text_content_length) {
+			node_ctx.textLength = atoi(val);
+		} else if (key == keys.prop_content_length) {
+			node_ctx.propLength = atoi(val);
+		} else if (key == keys.content_length) {
+			len = atoi(val);
+			buffer_read_line();
+			if (active_ctx == REV_CTX) {
+				read_props();
+			} else if (active_ctx == NODE_CTX) {
+				handle_node();
+				active_ctx = REV_CTX;
+			} else {
+				fprintf(stderr, "Unexpected content length header: %d\n", len);
+				buffer_skip_bytes(len);
+			}
+		}
+	}
+	if (active_ctx == NODE_CTX) handle_node();
+	if (active_ctx != DUMP_CTX) handle_revision();
+}
+
+static void svndump_init(void)
+{
+	repo_init();
+	reset_dump_ctx(~0);
+	reset_rev_ctx(0);
+	reset_node_ctx(NULL);
+	init_keys();
+}
+
+void svndump_reset(void)
+{
+	log_reset();
+	buffer_reset();
+	repo_reset();
+	reset_dump_ctx(~0);
+	reset_rev_ctx(0);
+	reset_node_ctx(NULL);
+}
diff --git a/vcs-svn/svndump.h b/vcs-svn/svndump.h
new file mode 100644
index 0000000..e205f1f
--- /dev/null
+++ b/vcs-svn/svndump.h
@@ -0,0 +1,7 @@
+#ifndef SVNDUMP_H_
+#define SVNDUMP_H_
+
+void svndump_read(char *url);
+void svndump_reset(void);
+
+#endif
-- 
1.7.1